Modification de The War: Concepts and Evolutions

{{Translations
| fr = La Guerre : conceptions et évolutions
| es = La Guerra: Concepciones y Evoluciones
| it = Guerra: concezioni e sviluppi
| de = Der Krieg: Konzeptionen und Entwicklungen
| lt = Karas: koncepcijos ir raida
}}

{{hidden
|[[Introduction to Political Science]]
|[[La pensée sociale d'Émile Durkheim et Pierre Bourdieu]] ● [[Aux origines de la chute de la République de Weimar]] ● [[La pensée sociale de Max Weber et Vilfredo Pareto]] ● [[La notion de « concept » en sciences-sociales]] ● [[Histoire de la discipline de la science politique : théories et conceptions]] ● [[Marxisme et Structuralisme]] ● [[Fonctionnalisme et Systémisme]] ● [[Interactionnisme et Constructivisme]] ● [[Les théories de l’anthropologie politique]] ● [[Le débat des trois I : intérêts, institutions et idées]] ● [[La théorie du choix rationnel et l'analyse des intérêts en science politique]] ● [[Approche analytique des institutions en science politique]]  ● [[L'étude des idées et idéologies dans la science politique]] ● [[Les théories de la guerre en science politique]] ● [[La Guerre : conceptions et évolutions]] ● [[La raison d’État]] ● [[État, souveraineté, mondialisation, gouvernance multiniveaux]] ● [[Les théories de la violence en science politique]] ● [[Welfare State et biopouvoir]] ● [[Analyse des régimes démocratiques et des processus de démocratisation]] ● [[Systèmes Électoraux : Mécanismes, Enjeux et Conséquences]] ● [[Le système de gouvernement des démocraties]] ● [[Morphologie des contestations]] ● [[L’action dans la théorie politique]] ● [[Introduction à la politique suisse]] ● [[Introduction au comportement politique]] ● [[Analyse des Politiques Publiques : définition et cycle d'une politique publique]] ● [[Analyse des Politiques Publiques : mise à l'agenda et formulation]] ● [[Analyse des Politiques Publiques : mise en œuvre et évaluation]] ● [[Introduction à la sous-discipline des relations internationales]]
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War is a complex phenomenon that has undergone numerous conceptions and evolutions over the course of history. Different eras and societies have had different perspectives on war, and these conceptions have evolved in response to political, economic, technological and social changes. 

War is armed conflict between states or groups, often characterised by extreme violence, social disruption and economic disruption. It generally involves the deployment and use of military forces and the application of strategies and tactics to defeat the adversary. War can have many causes, including territorial, political, economic or ideological disagreements. Modern warfare is generally considered to have originated with the emergence of the nation state in the 17th century. The Treaty of Westphalia in 1648 marked the end of the Thirty Years' War in Europe and established the concept of national sovereignty. This created an international system based on independent nation-states that could legitimately resort to war. Increasing the size of armies, improving military technology and evolving tactics and strategies also contributed to the birth of modern warfare. In an age of terrorism and globalisation, the nature of warfare is changing. We are now faced with asymmetric conflicts in which non-state actors, such as terrorist groups, play a major role. In addition, the rise of cybernetics has led to the emergence of cyberwarfare. Finally, information warfare, in which information is used to manipulate or mislead public opinion or the adversary, has become a common tactic.

The idea of the end of war is debated. Some argue that globalisation, economic interdependence and the spread of democratic values have made war less likely. Others argue that war is not about to disappear, citing the existence of ongoing armed conflicts, the persistence of international tensions and the possibility of future conflicts over limited resources or due to climate instability. What's more, while traditional conflicts between states may be diminishing, new forms of conflict, such as terrorism or cybernetics, are persisting. The future of war is uncertain, but what is certain is that the pursuit of diplomacy, dialogue and disarmament is essential to prevent war and promote lasting peace.

First, we will explore the fundamental nature of war, before looking at the emergence of modern warfare. We will see that war transcends mere violence and acts as a regulating element in our international system, which has been shaped over several centuries. We will then examine contemporary developments in warfare, particularly in the context of terrorism and globalisation, and ask whether the nature of warfare is changing and whether its fundamental principles are evolving. Finally, we look at the future of war: is it coming to an end, or does it persist in other forms?

= What is war? =

== Definition of war ==

We're going to ask ourselves what war is and look at some of the warnings and preconceived ideas about war. There are many definitions of war, but one of the most relevant is that of Hedley Bull, the founder of the English school, who, in his 1977 book The Anarchical Society: A Study of Order in World Politics, gives the following definition: "an organised violence carried on by political units against each other". 

Hedley Bull's definition of war highlights several key aspects of this complex phenomenon.

1 "Organised violence": The use of this phrase suggests that war is not a random or chaotic series of violent acts. It is organised and planned, often in great detail. This organisation may involve the mobilisation of troops, the development of strategies and tactics, the production and acquisition of weapons, and many other logistical aspects. The violence in question is also extreme, generally involving death and serious injury, destruction of property and social instability.

2. "Conducted by political units": Here, Bull emphasises that war is an act committed by political actors - typically nation-states, but also potentially politically organised non-state groups. This reflects the fact that war is often the product of political decisions and is used to achieve political objectives. This can include objectives such as the seizure of territory, regime change, the assertion of national power, or defence against a perceived threat.

3. "Against each other": This part of the definition emphasises that war involves conflict. It is not a question of unilateral acts of violence, but of a situation in which several parties actively oppose each other. This implies an interactive dynamic where the actions of each side influence the actions of the other, creating a cycle of violence that can be difficult to break.

This definition, while simple, encompasses many aspects of war. However, it is important to note that war is a complex phenomenon that cannot be fully understood or explained by a single definition. Many other perspectives and theories can also provide valuable insights into the nature of war, its origin, course and consequences.

The distinction between interpersonal violence, such as crime and aggression, and war, as organised violence carried out by political units, is crucial:
* Interpersonal violence: This refers to acts of violence committed by individuals or small groups, often in the context of crimes such as theft, assault, murder, etc. It is generally not coordinated or organised on a large scale, and is not intended to achieve political objectives. It is generally not coordinated or organised on a large scale, and is not intended to achieve political objectives. Motivations can be varied, ranging from personal conflict to the pursuit of material gain.
* War: Unlike interpersonal violence, war is a form of large-scale violence that is carefully organised and planned by political units, usually nation states or structured political groups. War aims to achieve specific, often political, objectives through the use of force. Combatants are usually trained and equipped soldiers or militants, and conflicts are often fought according to certain rules or conventions.

Hedley Bull's point about the official nature of war is crucial to understanding its nature. In his view, war is waged by political units, usually states, against other political entities. It is an action that is officially sanctioned and conducted in the name of the state. This distinction is important because it separates the notion of war from that of crime-fighting, which is also a form of organised violence but operates within a different framework. Whereas war is generally a conflict between states or political groups, crime control is an action undertaken by the state within its own borders to maintain order and security. Crime control is generally carried out by law enforcement agencies, such as the police, whose mission is to prevent and suppress crime. The aim is not to achieve political or strategic objectives, as is the case in war, but rather to protect citizens and uphold the law. This differentiation underlines the exceptional nature of war as an act of organised violence that transcends political boundaries, contrasts with internal violence, and is sanctioned by the state or political entity. War is inherently a political phenomenon, aimed at changing the status quo, often through the use of armed force, and therefore represents a distinct dimension of violence in society. 

Hedley Bull's definition of war is fairly complete and precise. It aptly describes the nature of modern warfare by highlighting its key aspects: it is organised violence, carried out by political units, between themselves, and generally directed outside these political units. This definition captures what many people mean by 'war', including those who study it in an academic or military context. It captures the notion that war is a structured phenomenon, with specific actors (political units), an official character, and an external orientation. This definition also serves as a basis for understanding the complexity of modern conflicts, where the lines between state and non-state actors can be blurred, and where conflicts can involve international actors and transcend national boundaries.

However, it should be noted that this definition, while useful, is only one of many possible ways of defining and understanding war. Other perspectives may emphasise other aspects of war, such as its social, economic or psychological dimensions. As with any complex phenomenon, a complete understanding of war requires a multidimensional approach that takes into account its multiple facets and implications.

== Deconstructing conventional wisdom ==
War as a concept has infiltrated our collective consciousness through history, the media, literature and other forms of cultural communication. However, our intuitive perceptions of war can be shaped by preconceptions that do not necessarily reflect the complexity of reality. 

[[File:Leviathan by Thomas Hobbes.jpg|thumb|right|Frontispiece of ''Leviathan''.]]

=== Thomas Hobbes' approach: "the war of all against all". ===
For Thomas Hobbes in The Leviathan, published in 1651, war is "the war of all against all". In this book, Hobbes describes the state of nature, a hypothetical condition in which there is no government or central authority to impose order. He defines the state of nature as a "war of all against all" (bellum omnium contra omnes in Latin), where individuals are in constant competition with each other for survival and resources. According to Hobbes, without a central authority to maintain order, human beings would be in constant conflict, leading to a life that would be "solitary, poor, unpleasant, brutish and short". This is why, in his view, human beings agree to give up part of their freedom in favour of a government or sovereign (Leviathan), which is capable of imposing peace and order. 

In "Leviathan", Hobbes argues that without a state or central authority, the lives of individuals would be in a constant state of "war of all against all". It is anarchy, Hobbes argues, that reigns in the absence of the state. Anarchy, in this context, does not necessarily mean chaos or disorganisation, but rather the absence of a central authority to impose rules and standards of conduct. For Hobbes, the state is therefore a necessary instrument for regulating inter-individual relations, preventing conflict and ensuring the security of individuals. According to Hobbes, individuals agree to give up part of their freedom in exchange for the security and stability that the state can provide.

In reality, even in situations of extreme social or political instability, human beings tend to form structures and organisations to preserve order and facilitate survival. Perpetual war, as described by Hobbes in the State of Nature, is practically impossible from an empirical point of view. Moreover, waging war requires a degree of organisation and coordination that individuals in a state of anarchy would find difficult to achieve. Individuals are more inclined to band together for their own defence or to achieve common goals, which in itself can be seen as a primitive form of state or governance. It is important to note that Hobbes uses the state of nature and the 'war of all against all' as conceptual tools to argue for the importance of the state and the social contract. He does not necessarily suggest that this state of nature ever existed literally. 

Armed conflicts, particularly those that rise to the level of war, involve much more complex dynamics than simple aggression or individual conflict. They require significant organisation, strategic planning and substantial resources.

Wars generally involve political actors - states or groups seeking to achieve specific political objectives. Thus, war is not only an extension of individual aggression or selfishness, but is also strongly linked to politics, ideology and power structures. Moreover, wars often have far-reaching social and political consequences. They can reshape borders, topple governments, bring about major societal changes, and have lasting effects on individuals and communities. For these reasons, the study of war requires a thorough understanding of many different aspects of human society, including politics, psychology, economics, technology and history.

Hobbes' vision of 'war of all against all' focuses on selfishness and conflict as inherent aspects of human nature. However, war, as we know it, is not simply the product of individual selfishness or aggression. It is in fact a complex social creation that requires substantial organisation and coordination. The idea that war is in fact a product of our sociality, and not of our egoism, is very enlightening. To wage war, you need not only resources, but also an organisational structure to coordinate efforts, an ideology or goal to unify participants, and norms or rules to regulate conduct. All these elements are the product of life in society. This perspective suggests that to understand war, we need to look beyond simple instincts or individual behaviour and consider the social, political and cultural structures that enable and shape armed conflict. It also emphasises that the prevention of war requires attention to these structures, and not just to human nature. 

Although the Hobbesian theory of "war of all against all" suggests that war is rooted in the selfish nature of individuals, the reality is much more complex. War requires a degree of organisation, planning and coordination, all of which are characteristics of human societies rather than isolated individuals. Consequently, war can best be understood as a social phenomenon, rather than as a simple extension of individual egoism or aggression. War is often influenced by, and in turn influences, a variety of social structures and processes, including politics, economics, culture, and social norms and values. Armed conflicts do not occur in a vacuum, but are deeply rooted in specific social and historical contexts.

War is much more than a simple manifestation of human aggression or selfishness. Rather, it is the result of a vast array of social and organisational factors that enable, facilitate and motivate large-scale conflict. To start a war, you need much more than a simple will or desire to fight. It requires organisational structures capable of mobilising resources, coordinating strategies and directing armed forces. These structures include bureaucratic administrations, military chains of command and logistical support systems, among others. These organisations cannot exist without the social framework that supports them. In addition, there must also be a certain type of culture and ideology that justifies and values war. Beliefs, values and social norms play a crucial role in the creation and maintenance of these organisations, as well as in motivating individuals to take part in war. War is therefore a profoundly social and structural phenomenon. It is the product of our ability to live together in society, and not of our selfishness or individual aggression. This perspective can offer important avenues for preventing conflict and promoting peace. 

=== Heraclitus' approach: War is the father of all things, and of all things it is king ===
We have just seen how to make war and make it possible, and now, with the second preconception, we are going to look at the "when". The second received wisdom is that of Heraclitus' perpetual war, which postulates that "War is the father of all things, and of all things it is king". However, this view oversimplifies reality. 

War, as we know it today, is a specific phenomenon that requires a certain level of social and organisational structure, as we discussed earlier. In other words, war is not simply a manifestation of human violence, but rather an organised and structured form of conflict that has evolved over time as a function of social, political, economic and technological factors. The presence of organised violence is not a universal feature of all human societies throughout history. Some societies have experienced prolonged periods of peace, while others have experienced higher levels of violence and conflict. Moreover, the nature of war itself has also changed significantly over time. Ancient warfare, for example, was very different from modern warfare in terms of strategy, technology, tactics and consequences.

If we take a slightly more sociological view, we could say that war is a relatively recent phenomenon in human history, or at least it is not a timeless characteristic. Archaeological and anthropological evidence indicates that war, as we understand it today as large-scale organised conflict between political entities, is a relatively recent phenomenon in human history. It is only with the emergence of more complex and hierarchical societies, often accompanied by sedentarisation and agriculture, that we begin to see clear signs of organised warfare. Before that, although interpersonal violence and small-scale conflicts certainly existed, there is no convincing evidence of large-scale conflicts involving complex coordination and political objectives. This is not to say that human societies were peaceful or without violence, but rather that the nature of this violence was different and did not correspond to what we generally call "war".

The idea that war is a recent phenomenon on the scale of human history is supported by a great deal of research in anthropology and archaeology. Before the advent of agriculture during the Neolithic Revolution around 7000 BC, humans generally lived in small hunter-gatherer groups. These groups did have conflicts, but they were generally small-scale and did not resemble the organised wars we know today. We can't really talk about war. War, as we define it today, requires a certain social organisation and specialisation of work, including the formation of groups dedicated to combat. Moreover, war often involves conflicts over the control of resources, which becomes more relevant with the emergence of agriculture and the sedentarisation of populations, when resources become more localised and limited. This is why most researchers agree that war, as a structured and organised phenomenon, probably did not exist before the Neolithic Revolution, around 10,000 years ago. This means that for most of human history, war as we know it did not exist, which calls into question the idea that it is a natural and inevitable aspect of human society. So, if we assume that man appeared 200,000 years ago, war would only have affected 5% of our history. We are far from an anhistorical and universal phenomenon that has always existed.  

It is important to avoid essentializing war as something that is in us. If we look empirically at the facts, war has not always existed and it is linked to a developed social organisation. This form of social organisation appeared from the Neolithic period onwards and coincided with functional specialisation, i.e. the appearance of the first towns. Thus, war as an organised and institutionalised phenomenon is intrinsically linked to the emergence of more complex societies, particularly with the birth of the first cities. City life led to a much more marked division of labour, with individuals specialising in specific trades, some of which were linked to defence and warfare. Hunter-gatherer societies often have a division of labour based on sex and age, but the diversity of roles is generally limited compared with what we see in more complex agricultural societies. With the development of agriculture and the first cities, the division of labour widened considerably, allowing the formation of classes of specialised warriors. This also coincided with the emergence of the first states, which had the resources and organisation needed to wage war on a large scale. It was at this time that we saw the emergence of forms of organised and prolonged violence that we recognise as wars.

It is an idea that is quite fundamental to the very idea of state-building and the development of our societies. The ability to organise and wage war has become a key element in the formation of states. In many cases, the threat of violence or war has contributed to the unification of diverse groups under a central authority, leading to the creation of nation states. This is reflected in Hobbes' theory of the social contract, in which he postulates that individuals agree to give up certain freedoms and grant authority to a supreme entity (the state) in exchange for security and order. In this sense, war (or the threat of war) can serve as a catalyst for the formation of states. Moreover, the management of war, through the raising of armies, the defence of territory, the application of international law and diplomacy, has become an essential part of the responsibilities of modern states. This is reflected in the development of dedicated bureaucracies, tax systems to fund military efforts, and internal and external policies focused on military and security issues. Thus, warfare and state formation are deeply intertwined, each influencing and shaping the other throughout human history. 

Professional specialisation has been a key factor in the development of human societies. This is known as the division of labour, a concept that has been widely explored by thinkers such as Adam Smith and Emile Durkheim. The division of labour can be described as a process by which the tasks necessary for the survival and functioning of a society are divided between its members. For example, some people may specialise in agriculture, while others specialise in construction, commerce, teaching or security. This specialisation allows each individual to develop skills and knowledge specific to their role, which generally increases the efficiency and productivity of the society as a whole. In turn, individuals depend on each other to meet their needs, creating a complex web of interdependence. In terms of security and the application of violence, specialisation has led to the creation of police forces and armies. These entities are responsible for maintaining order, protecting society and enforcing laws and regulations. This specialisation has also had significant implications for the conduct of war and the structuring of modern societies.

War, as we understand it today, coincides with the Neolithic Revolution, a period when humans began to settle down and create more complex social structures. Prior to this, inter-group conflicts existed, but they probably didn't have the same scale or level of organisation as what we now classify as 'war'. The Neolithic Revolution saw humans evolve from nomadic hunter-gatherers to sedentary farmers. This led to the creation of the first significant population density - cities - as well as the emergence of new forms of social and political structure. This increased population density and more complex structures probably increased competition for resources, which may have led to more organised conflict. In addition, with the emergence of cities, the specialisation of occupations began to develop. This specialisation included roles dedicated to the protection and defence of the community, such as warriors or soldiers, who could devote themselves entirely to these tasks rather than also having to worry about farming or hunting. This specialisation led to the emergence of more organised and effective military forces, contributing to the escalation of war as a social phenomenon.

After the Neolithic Revolution, we witnessed a rapid increase in social and political complexity. Sedentarisation and agriculture led to more stable and wealthier societies, capable of supporting a growing population. With this increase in population and wealth, competition for resources intensified, leading to an increase in conflicts. The first city-states, such as those of Sumer in Mesopotamia around 5000 BC, are an excellent example of this increase in complexity. These city-states were highly organised, hierarchical societies with a clear division of labour, including military roles. They had their own governments, legal systems, religions and, very often, they owned and controlled their own territory. These city-states competed for control of resources and territory, and this competition often resulted in war. The wars of the time were often official affairs, led by kings or similar rulers, and were an important part of the politics of the day. Over time, these city-states evolved into larger and more complex kingdoms and empires, such as the Egyptian Empire, the Assyrian Empire, and later the Persian, Greek and Roman empires. These empires led to even bigger and more complex wars, often involving thousands or even tens of thousands of soldiers.

== The Phalanx: Origins of Modern Organised Violence ==

During classical antiquity, and especially during the era of the Roman Empire, warfare took a qualitative leap forward in terms of organisational and technological complexity. 

In organisational terms, the Roman army became a veritable war machine, with a clear hierarchy, strict discipline, rigorous training and sophisticated logistics. The Roman army model, based on the legion as the basic unit, enabled the Romans to deploy forces quickly and efficiently over a vast territory. In terms of technology, the period also saw the introduction and spread of new weapons and war equipment. The Romans, for example, developed the pilum, a type of javelin designed to penetrate shields and armour. They also innovated in the construction of siege engines, such as catapults and battering rams.

The technological dimension of warfare was not limited to weapons and equipment. The Romans were particularly effective in using engineering to support their military efforts. For example, they built an extensive network of roads and bridges to facilitate the rapid movement of their troops. They also used their engineering know-how to build forts and fortifications, and to conduct complex siege operations. These organisational and technological innovations made warfare an increasingly complex and costly undertaking. However, they also helped to strengthen the power of empires like Rome, enabling them to conquer and control vast territories.

The evolution of warfare is closely linked to the growing complexity of societies. The phalanx is a perfect example of this. The phalanx was a combat formation used by the armies of ancient Greece. It was a heavy infantry unit made up of soldiers (hoplites) who stood side by side in close ranks. Each soldier carried a shield and was equipped with a long spear (sarissa), which he used to attack the enemy while remaining protected behind the shield of his neighbour. The phalanx was a highly organised and disciplined formation that required intensive training and precise coordination. Its main objective was to crush the enemy on initial impact, using the collective strength of the soldiers to break through the enemy lines.

This represented a great advance on the more haphazard fighting methods used previously. This more complex combat organisation reflected the more complex structure of Greek society at the time. Citizen-soldier armies had to be well disciplined and well trained to be able to use the phalanx effectively. During his military campaigns, Alexander the Great perfected the use of the phalanx, adding elements of cavalry and light infantry to create a more flexible and adaptable military force. This contributed to his military successes and the expansion of his empire.

The evolution of warfare has been greatly influenced by technological progress. As societies developed and became more complex, technology played an increasingly important role in the way wars were fought. From the phalanxes of ancient Greece, to the use of catapults and other siege engines during the Middle Ages, to the use of gunpowder in China and Europe, technology has always helped to shape military strategies. This trend has continued into the modern era with the rise of artillery, steam-powered warships, submarines, aircraft, tanks and finally nuclear weapons. More recently, cyber warfare and armed drones have become key elements of the contemporary battlefield. Technology has not only influenced tactics and combat strategies, but has also transformed logistics, communications and military intelligence. It has enabled military action to be taken faster, more effectively and on a larger scale.[[File:Syntagma phalangis.jpg|thumb|350px|center|Macedonian phalanx.]]

The Middle Ages were marked by a change in the way war was waged. The fall of the Roman Empire meant a loss of the advanced military organisation and technology of the Romans. Conflicts at this time were often more feudal in nature, involving knights and local lords, and battles were often smaller and more dispersed. Warfare focused more on sieges of castles and raids than on large, pitched battles.

In the 15th century, with the onset of the Renaissance and the formation of the first modern nation-states, we witnessed a new transformation in warfare. Technological innovation, in particular the introduction of artillery and firearms, changed the dynamics of warfare. Military organisation has become more centralised and structured, with standing armies commanded by the state.

The modern state also played a major role in the transformation of warfare. Nation states began to assume responsibility for the defence and security of their citizens. This led to the creation of military bureaucracies, recruitment and training systems, and a logistical infrastructure to support standing armies. The modern state has also enabled resources to be mobilised on a much larger scale than was possible under previous feudal systems. These changes had a profound influence on the nature of warfare and laid the foundations for warfare as we know it today.

== The Influence of War on Political Modernity ==
Putting the long history of humanity into perspective, war as we understand it today is a relatively recent phenomenon. Its presence is closely linked to the emergence and development of more complex social and political structures. Going back to the Stone Age, we find little evidence of large-scale organised violence. The appearance of war is generally associated with the advent of civilisation, which began with the Neolithic Revolution, when human beings began to settle down and create more organised societies. With the appearance of the first city-states around 5000 BC, war became a more common phenomenon, as these political entities competed for territory and resources. War took on a more organised and structured form, with standing armies and a military strategy. The development of modern warfare from the 17th century onwards coincided with the emergence of the modern state. With greater resources and a centralised administrative structure, nation states were able to wage war on an unprecedented scale and with unprecedented intensity. 

The history of war is also the history of the state. On the one hand, the threat of war can encourage the creation of states. Faced with hostile neighbours, communities may choose to unite under a single political authority to defend themselves. The modern state was often born out of this process, as illustrated by Thomas Hobbes' famous quote: "Man is a wolf to man". On the other hand, the conduct of war requires large-scale organisation and coordination. States have provided this structure, by raising armies, imposing taxes to finance military campaigns, and establishing military strategies and policies. In times of war, states have often increased their power and reach, both over their own citizens and over the territory they control. Finally, wars have often changed the form and nature of states. Conflict can lead to the dissolution or creation of new states, as illustrated by the history of the twentieth century, which saw the end of many colonial empires and the creation of new nation states. It is difficult to understand the history of the state without considering the role of war, and vice versa.

War and the modern state are profoundly linked in political history. This relationship is central to understanding the evolution of human societies and the form that armed conflict takes. The modern state, as it developed in Europe from the 17th century onwards, is characterised by the centralisation of power and a monopoly on the legitimate use of force. The formation of nation states and the emergence of the Westphalian system coincided with a major transformation in the nature of warfare. Firstly, the modern state has institutionalised war. The state has a monopoly on the legitimate use of force, and war has become a state affair. This development has led to the establishment of rules and structures for the conduct of war. Secondly, the modern state has professionalised warfare. With the centralisation of power, states were able to maintain standing armies. This has led to increasingly organised and technologically advanced warfare. Thirdly, the modern state has nationalised war. In pre-modern societies, wars were often fought by lords or chiefs acting in their own name. With the modern state, war has become a matter for the nation as a whole. War, as we understand it today, is a creation of the modern state. It is the product of the evolution of human political organisation and the concentration of power in the hands of the state.

The state, as we understand it today, is a specific form of political organisation that emerged at a particular period in history. There are many other forms of political organisation that have existed throughout history and still exist today in certain parts of the world. Empires, for example, were a common form of political organisation in ancient times and up until the beginning of the 20th century. They were characterised by a central authority (usually an emperor or king) that dominated a number of different territories and peoples. City-states were another form of political organisation, particularly widespread in ancient Greece and Renaissance Italy. In this system, a city and its surrounding territory formed an independent political entity. Colonies are also a form of political organisation, although often under the domination of another political entity (such as an empire or a state). Colonies were particularly common during the era of European imperialism from the 16th to the 20th centuries. That said, while the state is a specific and relatively recent form of political organisation, it has had a profound influence on the nature of warfare and how it is conducted. This is why the study of the state is so important to understanding modern warfare.[[File:Arc-et-Senans - Plan de la saline royale.jpg|thumb|250px|right|Arc-et-Senans - Plan of the royal saltworks.]]

The state is often seen as a necessary structure to ensure social stability, security, respect for the law and the provision of essential public services such as education, health, transport, etc. However, this positive perception of the state should not prevent us from understanding the more complex and sometimes problematic aspects of the state's existence. However, this positive perception of the state should not prevent us from understanding the more complex and sometimes problematic aspects of the state's existence. One aspect relates to the state's monopoly of legitimate violence, according to Max Weber's classic sociological theory. This monopoly allows the state to maintain order and enforce the law, but it also allows the state to wage war. The fact that war is generally waged by states, and that it is intrinsically linked to the birth and development of the modern state, is a reminder that the state is not only a force for stability and well-being, but can also be a source of violence and conflict. This is something we need to bear in mind when we think about the state and its role in society. War, violence and conflict are not mere aberrations, but an integral part of the nature of the state. This is why understanding war is so essential to understanding the state.

One of the main functions of the state is to maintain peace and order within its borders. This is achieved through a range of institutions, such as the police force and the judiciary, which are responsible for upholding the law and preventing or resolving conflicts between citizens. The state is often seen as the guarantor of security and stability, and this is one of the reasons why citizens agree to cede some of their freedom and power to it. However, the situation is very different beyond the borders of the state. At international level, there is no entity comparable to a state that is capable of enforcing law and order. Relations between states are often described as being in a state of "anarchy" in the sense that there is no higher central authority. This can lead to conflict and war, as each state has the freedom to act as it sees fit to defend its interests.

The State plays a major role in maintaining international peace. As a participant in international organisations such as the UN, WTO, NATO and others, the state helps to formulate and respect international norms and rules, which are essential for preventing and managing conflicts between nations. Furthermore, by signing and abiding by international treaties, states actively participate in the creation of a rules-based world order, which contributes to international stability and security. In this sense, the state is seen as an essential player in modern civilisation, capable of establishing and maintaining order, promoting cooperation and avoiding chaos and anarchy. This is generally seen as a positive development compared with previous historical periods, when violence and war were more common means of resolving conflicts.

One of the main justifications for the existence of the state is its ability to maintain order and prevent chaos. The concept of "monopoly of legitimate violence" is fundamental here. According to this concept, formulated by the German sociologist Max Weber, the state has the exclusive right to use, threaten or authorise physical force within the limits of its territory. In this sense, the state is often seen as an antidote to the Hobbesian 'state of nature', where, in the absence of any centralised power, life would be 'solitary, poor, brutal and brief'. The state is therefore often seen as the actor that makes it possible to maintain order, prevent chaos and anarchy, and ensure the security of its citizens.

An effective state is generally able to maintain public order, ensure the safety of its citizens and provide essential public services, thereby contributing to social stability and peace. However, in areas where the state is weak, absent or ineffective, situations of chaos can arise. Conflict zones, for example, are often characterised by the absence of a functioning state capable of maintaining law and order. Similarly, in failed or failing states, the inability to provide security and basic services can lead to high levels of violence, crime and instability.

Mass violence, such as genocide, is a phenomenon that has been greatly facilitated by the emergence of the modern state and industrial technology. Bureaucratic efficiency, the ability to mobilise and control vast resources, which are typical features of modern states, can unfortunately be misused for destructive purposes. Take the example of the Shoah during the Second World War. The systematic and large-scale extermination of Jews and other groups by the Nazis was made possible by the modern industrial state and its bureaucratic apparatuses. Similarly, the Rwandan genocide in 1994, in which some 800,000 Tutsis were killed in the space of a few months, was perpetrated on a massive scale and with terrifying efficiency largely thanks to the mobilisation of state structures and resources.

The two world wars are typical examples of total war, a concept that describes a conflict in which the nations involved mobilise all their economic, political and social resources to wage war, and in which the distinction between civilians and military combatants is blurred, exposing the entire population to the horrors of war. The First World War introduced the industrialisation and mechanisation of warfare on an unprecedented scale, with the massive use of new technologies such as heavy artillery, aircraft, tanks and poison gas. The violence of this war was amplified by the total involvement of the belligerent nations, with their economies and societies completely mobilised for the war effort. The Second World War further intensified the concept of total war. It was characterised by the massive bombing of entire cities, the systematic extermination of civilian populations and the use of nuclear weapons. This war also saw the large-scale use of propaganda, the exploitation of the war economy and the massive mobilisation of manpower. Total war is another manifestation of the way in which modernity and the modern state have allowed new forms of violence to emerge on a massive scale.

The twentieth century was marked by unprecedented violence as a result of two world wars, numerous regional conflicts, genocides and totalitarian regimes. This level of violence is often attributed to a combination of factors, including the emergence of powerful modern states, the availability of weapons of mass destruction and extreme ideologies. The world wars caused tens of millions of deaths. In addition, other conflicts such as the Korean War, the Vietnam War, the Armenian genocide, the Holocaust, the Rwandan genocide and the Stalinist and Maoist purges resulted in the deaths of millions more. Internal political violence, often carried out by totalitarian regimes, was also a major source of violence in the twentieth century. Regimes such as Stalin's in the Soviet Union, Mao's in China, Pol Pot's in Cambodia and many others used political violence to eliminate opponents, achieve ideological goals or maintain power. In short, the violence of the twentieth century shows just how double-edged modernity and the modern state have been: on the one hand, they have allowed an unprecedented level of development, prosperity and stability in many parts of the world; on the other, they have allowed an unprecedented level of violence and destruction.

The modern state, with its sovereignty, defined territory, population and government, is expected to offer its citizens protection from violence. It is supposed to guarantee order and stability through the rule of law, efficient administration and the protection of its citizens' rights and freedoms. However, the history of the 20th century shows that the modern state can also be a major source of violence. World wars, regional conflicts, genocide and political purges have largely been perpetrated or facilitated by modern states. These forms of violence are often linked to the exercise of state power, the defence of the established order, or the application of certain ideologies or policies. The modern state therefore has two faces. On the one hand, it can guarantee order, security and stability, and provide a framework for prosperity and development. On the other hand, it can be a major source of violence and oppression, particularly when it is used for the purposes of war, political repression or the achievement of certain ideological goals. It is important to understand this paradox if we are to grasp the complexity of the political and social challenges we face in the modern world.

=	The evolution of war throughout history =

== War as the Builder of the Modern State ==

[[Fichier:Passage de la Seine par armee anglaise et pillage Vitry XIVe siecle.jpg|vignette|droite|The crossing of the Seine and the sack of Whittier by English troops in the 14th century.]]

To study war, we must first focus on its links with the modern state as a political organisation. We are going to see how war today is shaped by and through the emergence of the modern state. We shall begin by seeing that war is a matter for the State. In order to introduce the idea that war is linked to the very construction of the State and the emergence of the State as a form of political organisation in Europe from the end of the Middle Ages, the best way to do this is as the sociohistorian Charles Tilly put it in his article ''War Making and State Making as Organised Crime'', which developed the idea of war making/state making: it was by making war that we made the State, and vice versa. 

In 'War Making and State Making as Organized Crime', Charles Tilly offers a provocative socio-historical analysis of modern state-building in Western Europe. He argues that the processes of state-building and warfare are intrinsically linked, and even compares states to criminal organisations to highlight the coercive and exploitative aspects of their formation. According to Tilly, the formation of modern states is largely driven by the efforts of ruling elites to mobilise the resources needed for war. To this end, these elites resort to means such as taxation, conscription and expropriation, which can be likened to forms of racketeering and extortion. Furthermore, Tilly argues that state-building was also facilitated by the monopolisation of the use of legitimate force. In other words, rulers sought to eliminate or subordinate all other sources of power and authority in their territory, including feudal lords, corporations, guilds and armed bands. This process often involved the use of violence, coercion and political manipulation. Finally, Tilly points out that state-building also required the construction of a social consensus, or at least the acquiescence of populations, through the development of a national identity, the establishment of social and political institutions, and the provision of services and protections. This analysis offers a critical and scathing perspective on the construction of modern states, highlighting their violent and coercive roots, while underlining their key role in structuring our contemporary societies. 

The conception of the modern state as we know it today is mainly based on the European model, which emerged during the Renaissance and Modern periods, between the 14th and 17th centuries. This evolution was marked by the centralisation of political power, the formation of defined national borders, the development of an administrative bureaucracy and the monopolisation of the use of legitimate force by the state. However, it is important to note that other political models exist elsewhere in the world, based on different historical, cultural, social and economic trajectories. For example, in some societies, the political structure may be more decentralised, or based on different principles, such as reciprocity, hierarchy or equality. Furthermore, the process of exporting the European state model, notably through colonisation and more recently through state-building or nation-building, has often met with resistance and may have led to conflict and tension. This is often due to the fact that these processes can fail to take account of local realities and can sometimes be perceived as forms of cultural or political imposition.

In his article "War Making and State Making as Organized Crime", Charles Tilly proposes a framework for understanding the state formation process, particularly on Europe between the 15th and 19th centuries. Tilly sees the emergence of the state as the product of two interconnected dynamics: war making and state making.

* War making: Tilly postulates that states have been shaped by a constant need to prepare for, wage and finance war. Wars, particularly in the European context, have been key factors in the development of state structures, not least because of the resources needed to wage them.
* State making: This is the process by which the central power of a state is consolidated. For Tilly, this involved controlling and neutralising its internal rivals (notably the feudal lords) and imposing its authority over the entire territory under its control.

These two processes are closely linked, as wars provide the impetus for the consolidation of the state, while themselves being made possible by this consolidation. For example, to finance wars, states had to set up more efficient tax and administrative systems, strengthening their authority.

=== War and the Modern State ===
[[Fichier:Einhard vita-karoli 13th-cent.jpg|vignette|right|Ilustración manuscrita del siglo XIII de Vita Karoli Magni.]]

The feudal system was a complex structure of relations between lords and the king, based on land ownership (or "fiefs") and loyalty. Lords had a great deal of autonomy over their lands and were generally responsible for security and justice on their lands. In exchange for their fief, they had to swear allegiance to the king and provide him with military support when he needed it. This system of vassalage formed the basis of power during the Middle Ages. However, with the advent of the modern state, this system was gradually replaced. The consolidation of the state was accompanied by an effort to centralise power, which often involved abolishing or reducing the power of feudal lords. A key element in this process was the need to finance and support warfare. Kings began to develop administrative and fiscal structures to raise funds and recruit armies directly, rather than relying on feudal lords. This strengthened their authority and enabled the formation of more centralised and bureaucratic states. 

According to Charles Tilly, war was a powerful driving force behind the formation of the modern state. In the Middle Ages, competition between lords to expand their territory and increase their power often led to conflict. Lords were constantly at war with each other, seeking to gain control of each other's lands and resources. What's more, these local conflicts were often linked to wider conflicts between kingdoms. Kings needed a solid power base to support their war efforts, which led them to seek to strengthen their control over their lords. These dynamics created constant pressure for greater centralisation and more efficient organisation. The kings developed more sophisticated administrations and more efficient tax systems to support their war efforts. At the same time, they sought to limit the power of the feudal lords and assert their own authority. These processes laid the foundations of the modern state.[[Fichier:France sous Louis XI.jpg|300px|vignette|right]]

Norbert Elias, a German sociologist, developed the concept of "eliminatory struggle" in his work "The Civilizing Process". In this context, it refers to a competition in which the players eliminate each other until only a few, or even one, remain. In the context of state formation, this can be seen as a metaphor for the way in which feudal lords fought for power and territory during the Middle Ages. Over time, some lords were eliminated, either by military defeat or by assimilation into larger entities. This process of elimination contributed to the centralisation of power and the formation of the modern state. 

Over the centuries, many French kings gradually strengthened their power, seizing territories from the feudal nobility and consolidating central authority. These efforts were often supported by strategic marriage alliances, military conquests, political arrangements and, in some cases, the natural or forced extinction of certain noble lines. Louis XI, in particular, played a crucial role in this process. King from 1461 to 1483, he was nicknamed "l'Universelle Aragne" or "the Universal Spider" because of his cunning and manipulative policies. Louis XI worked hard to centralise royal power, reducing the influence of the great feudal lords and establishing a more efficient and direct administration throughout the kingdom. This contributed to the formation of the modern state, with centralised power and organised administration, which would be strengthened over the centuries, notably with Francis I and Louis XIV, the "Sun King".

France and Great Britain are often cited as typical examples of the emergence of the modern state. In France, the kings gradually centralised power, creating a more direct and efficient administration. The apogee of this centralisation was probably reached during the reign of Louis XIV, who declared "I am the State" and ruled directly from his palace at Versailles. However, this process was interspersed with periods of conflict and revolt, such as the Fronde and, later, the French Revolution. Great Britain, on the other hand, followed a slightly different path towards the formation of the modern state. King Henry VIII consolidated royal power by establishing the Church of England and abolishing monasteries, but Britain also saw a strong movement to limit royal power. This culminated in the Glorious Revolution of 1688 and the establishment of a constitutional system in which power was shared between the King and Parliament. In both cases, war played a major role in the formation of the state. The need to raise armies, levy taxes to finance wars and maintain internal order contributed greatly to the centralisation of power and the creation of efficient administrative structures.

External competition, particularly from the Renaissance onwards and during the modern era, was a major driving force in the formation of states and the structuring of the international system as we know it today. This can be seen in the development of diplomacy, alliances and treaties, wars for the conquest and control of territories, and even colonial expansion. It also led to the clearer definition of national borders and the recognition of state sovereignty. In particular, the involvement of Louis XI and his successors in the wars in Italy and against England played an important role in consolidating France as a state and in defining its borders and national interests. Similarly, the competition between European powers for territories abroad during the era of colonisation also helped to shape the international system.

The imperial ambitions of rulers such as Louis XI were partly motivated by the desire to consolidate their power and authority, both internally and externally. They needed resources to wage wars, which often meant demanding higher taxes from their subjects. These wars also often had a religious dimension, with the idea of reunifying the Christian world. As these kingdoms developed and began to clash with each other, an international system began to take shape. It was a slow and often confrontational process, with many wars and political conflicts. But over time, these states began to recognise each other's sovereignty, to establish rules for international interactions and to develop institutions to facilitate these interactions.

All this has led to the formation of a system of interconnected nation-states, in which each state has its own interests and objectives, but also a certain obligation to respect the sovereignty of other states. This is the foundation of the international system we have today, although the specifics have evolved over time.

=== The Role of War in the Interstate System ===
To wage war (war-making), a state must mobilise significant resources. This includes material resources, such as money to finance the army and buy weapons, food to feed the army, and materials to build fortifications and other military infrastructure. It also requires human resources, such as soldiers to fight and workers to produce the necessary goods. To obtain these resources, the state must be able to exercise effective control over its territory and its inhabitants. This is where state-making comes in. The state must set up effective taxation systems to collect the money needed to finance the war. It must also be able to recruit or conscript soldiers, which may require efforts to instil a sense of loyalty or duty to the state. In addition, it must be able to maintain order and resolve conflicts within its borders, so that it can concentrate on the war outside. So war and state-building are intimately linked. One requires the other, and the two reinforce each other. As Charles Tilly wrote, "States make wars and wars make States". 

The need to wage war led states to develop an efficient bureaucracy capable of collecting resources and organising an army. This process strengthened the state's ability to govern its territory and its inhabitants, in other words its sovereignty. To register the population, collect taxes and recruit soldiers, the state had to set up an administration capable of managing these tasks. This involved developing systems to record information about the inhabitants, establishing laws on taxes and conscription, and creating bodies to enforce these laws. Over time, these bureaucratic systems evolved to become increasingly efficient and sophisticated. They also helped to reinforce the authority of the state, by ensuring that its legitimacy was accepted by the people. People were more inclined to pay taxes and serve in the army if they believed that the state had the right to ask them to do so. War played a central role in the process of state-building, not only by encouraging the development of an efficient bureaucracy, but also by reinforcing the authority and legitimacy of the state.

According to Charles Tilly, the modern state developed out of a long-term process known as 'war making' and 'state making'. This theory argues that wars were the main driving force behind the growth of state power and authority in society. Tilly's theory suggests that the modern state was formed in a context of conflict and violence, where the ability to wage war and effectively control territory were key factors in the survival and success of the state.

After the end of the Middle Ages, Europe entered a period of intense competition between emerging nation states. These states sought to extend their influence and assert their dominance over others, which often led to wars. One of the most emblematic examples of this era is Napoleon Bonaparte. As Emperor of France, Napoleon sought to establish French dominance over the European continent, creating an empire that stretched from Spain to Russia. His attempt to create a borderless and inclusive empire was in reality an attempt to subjugate other nations to the will of France. However, this period of rivalry and war also saw the consolidation of the nation state as the principal form of political organisation. States strengthened their control over their territory, centralised their authority, and developed bureaucratic institutions to administer their affairs. The emergence of the modern nation-state in the post-medieval period was largely the product of imperial ambitions and inter-state rivalries. These factors led to the establishment of an interstate system based on sovereignty and war as a means of resolving conflicts. And this development has had a profound impact on our world today. 

After a period of intense war and conflict, a certain balance of power was established between the European nation states. This balance, often referred to as the "balance of power", has become a fundamental principle of international politics. The balance of power assumes that national security is ensured when military and economic capabilities are distributed in such a way that no single state is able to dominate the others. This encourages cooperation and peaceful competition and, in theory, helps prevent wars by discouraging aggression. This process has also led to the stabilisation of borders. States finally recognised and respected each other's borders, which helped to ease tensions and maintain peace.

From there, the idea of sovereignty emerged, meaning that the idea of authority over territory was divided between areas over which sovereignties were exercised that were mutually exclusive. Sovereignty is a fundamental principle of the modern international system, based on the notion that each state has supreme and exclusive authority over its territory and population. This authority includes the right to make laws, to enforce those laws and to punish those who break them, to control borders, to conduct diplomatic relations with other states and, if necessary, to declare war. Sovereignty is intrinsically linked to the notion of the nation state and is fundamental to understanding the dynamics of international relations. Each state is considered to have the right to manage its own internal affairs without external interference, which is recognised as a right by other states in the international system.

Ultimately, the principle of sovereignty gave rise to a universalism of the nation-state that was not that of the Empire, since the principle of sovereignty was recognised by all as the organising principle of the international system. The principle of sovereignty and equality between all States is the foundation of the international system and of the United Nations. This means that, in theory, every state, whether large or small, rich or poor, has a single vote at the United Nations General Assembly, for example. This follows from the principle of sovereign equality, which is enshrined in the United Nations Charter. Article 2, paragraph 1 of the UN Charter states that the Organisation is based on the principle of the sovereign equality of all its members.  

The idea of the United Nations stems from the idea of the principle of sovereignty as the organiser of the international system. This interstate system that is being set up is organised around the idea that there is a logic of internal equilibrium where the State administers a territory, i.e. the "police"; and external equilibrium where it is the States among themselves that settle their affairs. This distinction is central to the concept of state sovereignty. It is the state that has the prerogative and duty to manage internal affairs, including implementing laws, ensuring public order, providing public services and administering justice. This is known as internal sovereignty. External sovereignty is the right and capacity of a state to act autonomously on the international stage. This includes the right to enter into relations with other states, to sign international treaties, to participate in international organisations, and to conduct its foreign policy in accordance with its own interests.

Once all these states have been formed, they must communicate with each other. Since each of them has to survive as a state and there are other states, how are they going to communicate? If we start from the principle that war is an institution, it serves to do exactly that. War, as an institution, has been a way for states to communicate with each other. This does not necessarily mean that war is desirable or inevitable, but it has certainly played a role in the formation of states and the definition of relations between them. In European history, for example, wars have often been used to resolve conflicts over territory, power, resources or ideology. The results of these wars have often led to changes in borders, alliances and the balance of power between states.

According to John Vasquez, war is a learned form of political decision-making in which two or more political units allocate material goods or goods of symbolic value on the basis of violent competition. John Vasquez's definition highlights the violent competition aspect of war. According to this view, war is a mechanism by which political units, usually states, resolve their disagreements or rivalries. This may involve issues of power, territory, resources or ideologies. This definition underlines a vision of war that is firmly rooted in a realist tradition of thought in international relations, which sees international politics as a struggle of all against all, where conflict is inevitable and war is a natural tool of politics. 

We are moving away from the idea of war as something anarchic or violent; war is something that has been developed in its modern conception in order to settle disputes between states, it is a conflict resolution mechanism. This seems counter-intuitive because war is generally associated with anarchy and violence. However, in the context of international relations and political theory, war can be understood as a mechanism for resolving conflicts between states, despite its tragic consequences. This perspective does not seek to minimise the violence and destruction caused by war, but rather to understand how and why states choose to use military force to resolve their disagreements. According to this perspective, war is not a state of chaos, but a form of political conduct governed by certain norms, rules and strategies. This is why war is often described as a "continuation of politics by other means" - a famous phrase by the military theorist Carl von Clausewitz. This means that war is used by states as a tool to achieve political objectives when other means fail.

War can be understood as an ultimate conflict resolution mechanism, used when disagreements cannot be resolved by other means. This process requires the mobilisation of significant resources, such as armed forces, financed by the tax revenues of the belligerent states. The ultimate aim is to reach an agreement, often determined by the outcome of the fighting. However, victory does not necessarily mean a final settlement of the conflict in favour of the victor. The outcome of the war may lead to compromises, political and territorial changes, and sometimes even the emergence of new disputes.[[Fichier:1280px-Ajaccio tempesti bataille.JPG|vignette|left|Scène de bataille au Musée Fesch d'Ajaccio par Antonio Tempesta.]]

War can be viewed from a number of angles, depending on the perspective adopted. Viewed from a humanitarian perspective, it is often seen in terms of the suffering and loss of life it causes. From this perspective, questions emerge about the protection of civilians, human rights and the consequences for the socio-economic development of the affected areas. From a legal point of view, war involves a complex set of regulations and international laws, including international humanitarian law, the law of war and various international agreements and treaties. These regulations aim to limit the impact of war, in particular by protecting civilians and banning certain practices and weapons. However, despite these regulations, the legal stakes remain high, especially when it comes to determining the legitimacy of an armed intervention, assessing responsibilities in the event of a violation of international law, and managing post-conflict consequences such as transitional justice and reconstruction.  

In short, war, as a conflict resolution mechanism, is a complex phenomenon that involves humanitarian, political, economic and legal issues. This course takes a political science angle to look at where this phenomenon comes from and what it is used for. We are not interested here in the normative dimension of war.

We are coming to the idea that war is a mechanism for resolving conflicts and that therefore, if strategy has an end, the end and the goal of this strategy is peace. The ultimate aim of military strategy is often to establish or restore peace, even if the path to achieving it involves the use of force. This idea has its origins in the writings of several military thinkers, the most famous of whom is perhaps Carl von Clausewitz. In his book "On War", Clausewitz described war as "the continuation of politics by other means". This perspective suggests that war is not an end in itself, but a means to achieve political objectives, which may include the establishment of peace. Moreover, in the tradition of international relations theory, war is often seen as an instrument that states can use to resolve disputes when they fail to reach agreement by peaceful means. Thus, although war is a violent and destructive act, it can be seen as part of a wider process aimed at restoring stability and peace.

The two are linked. We have a concept where peace is intimately linked to war and, above all, the definition of peace is intimately linked to war. Peace is understood as the absence of war. It's interesting to see how the aim of strategy is to win and return to a state of peace. It is really war that determines this state. There is a very strong dialectic between the two. We are interested in the relationship between war and the state, but also between war and peace. This is a fundamental relationship that we won't be looking at today. In many theoretical frameworks, peace is defined in opposition to war. In other words, peace is often conceptualised as the absence of armed conflict. This view is called "negative peace", in the sense that peace is defined by what it is not (i.e. war) rather than by what it is. Military strategy often aims to restore this state of 'negative peace' by winning the war or achieving favourable conditions for ending the conflict.

We speak of peace because what is important is that in the conception of war that is being put in place with the emergence of this interstate system, i.e. with states being formed internally and competing with each other externally, war is not an end in itself, the goal is not the conduct of war itself, but peace; war is waged in order to obtain something. This is Raymond Aron's view. Raymond Aron, a French philosopher and sociologist, is famous for his work on the sociology of international relations and political theory. In his view, war is not an end in itself, but a means to achieve peace. This means that war is a political instrument, a tool used by states to achieve specific objectives, generally with the aim of resolving conflicts and achieving peace. From this perspective, war is an extreme form of diplomacy and negotiation between states. It is an extension of politics, carried out when peaceful means fail to resolve disputes. It is for this reason that Aron declared that "peace is the end, war is the means".

The concept of war as a conflict resolution mechanism is based on the idea that war is a tool of politics, a form of dialogue between states. It is used when peaceful means of conflict resolution have failed or when the objectives cannot be achieved by other means. From this perspective, states use war to achieve their strategic objectives, whether to protect their territorial interests, extend their influence or strengthen their security. These objectives are generally guided by a clearly defined military strategy, which aims to maximise the effectiveness of the use of force while minimising losses and costs.

== Carl von Clausewitz's Approach to War ==

[[Fichier:Clausewitz.jpg|vignette|200px|droite|Carl von Clausewitz.]]

Carl von Clausewitz, a Prussian officer in the early 19th century, played a decisive role in the theorisation of war. He wrote "On War" (Vom Kriege in German), which has become one of the most influential texts on military strategy and the theory of war. 

Carl von Clausewitz served in the Prussian army during the Napoleonic Wars, which lasted from 1803 to 1815. During this period, he gained valuable experience of combat and military strategy, which influenced his theories of war. Clausewitz took part in several major battles against Napoleon's army, and witnessed the dramatic changes in the way wars were fought in the early 19th century. It was during this period that he began to develop his theory that war is an extension of politics. After the end of the Napoleonic Wars, Clausewitz continued to serve in the Prussian army and began writing his major work, "On War". However, he died before he could complete the work, which was published posthumously by his wife.

Clausewitz said that war is "the continuation of politics by other means". This quotation, probably Clausewitz's most famous, expresses the idea that war is an instrument of national policy, and that military objectives must be guided by political objectives. In other words, war is a political tool, not an end in itself. Clausewitz also emphasised the importance of the "fog of war" and "friction" in the conduct of military operations. He argued that war is inherently uncertain and unpredictable, and that commanders and strategists must be able to manage these uncertainties. Despite his death in 1831, Clausewitz's thinking continues to exert a major influence on military and strategic theory. His work is studied in military academies around the world and remains an essential reference in the field of military strategy.

Clausewitz defines war as an act of violence designed to force an adversary to carry out our will. This is a very rational framework, not the logic of a "war madman". War is fought to achieve something. Carl von Clausewitz conceptualised war as an act of violence aimed at forcing an adversary to carry out our will. According to him, war is not an irrational or chaotic undertaking, but rather an instrument of policy, a rational means of pursuing a state's objectives. In his major work "On War", Clausewitz develops this idea by asserting that war is simply the continuation of politics by other means. In other words, states use war to achieve political objectives that they cannot achieve by peaceful means.

Imagine a state that is a government with the objective of acquiring fertile land to improve its economy or food security. As its neighbour is unwilling to give up this land voluntarily, the state chooses to resort to war to achieve its objective. If the warring state is victorious, it is likely that a peace treaty will be drawn up to formalise the land transfer. This treaty could also include other provisions, such as war indemnities, arrangements for displaced populations and a promise of future non-aggression. The initial objective (the acquisition of fertile land) was thus achieved by means of war, which was used as an instrument of policy.

This conception of war, as expressed by Clausewitz, highlights the fact that war is an extension of politics by other means. In this context, war is seen as a tool of politics, an option that can be employed when other methods, such as diplomacy or trade, have failed to resolve conflicts between states.

It is essential to understand that, according to Clausewitz, war is not an autonomous entity, but rather an instrument of policy that is controlled and directed by the political authorities. In other words, the decision to declare war, as well as the management and conduct of the war, are the responsibility of political leaders. Military objectives are therefore subordinate to political objectives. In Clausewitzian thinking, war is a means of achieving political objectives that cannot be achieved by other methods. However, it is always seen as a temporary solution and not as a permanent state. War is therefore not an end in itself, but a means to an end: the political objective defined by the state. Once this objective has been achieved, or when it is no longer possible to achieve it, the war ends and we return to a state of peace. This is why the notion of peace is intrinsically linked to that of war: war aims to create a new state of peace that is more favourable to the state waging it.

== The Westphalian system ==
The Westphalian system, named after the Treaty of Westphalia that ended the Thirty Years' War in 1648, profoundly influenced the international political structure and understanding of war. This series of treaties enshrined the notion of state sovereignty, establishing the idea that each state has exclusive authority over its territory and population, without outside interference. It also formalised the idea of non-interference in the internal affairs of other states. As for war, the Westphalian system helped to formalise it as an activity between states, rather than between factions or individuals. It also encouraged the development of rules and norms governing the conduct of war, although this process really took off in later centuries with the development of international humanitarian law. Thus, while war continued to be seen as a tool of foreign policy, the Westphalian system began to introduce constraints and rules for its use. These constraints were reinforced by the development of international law over the following centuries.

Hugo Grotius, also known as Hugo de Groot, was a central figure in the development of international law, particularly with regard to the laws of war and peace. His most famous work, "De Jure Belli ac Pacis" ("On the Law of War and Peace"), published in 1625, is considered one of the fundamental texts of international law. In this work, Grotius seeks to define a set of rules governing the behaviour of states in times of war and peace. He examines in detail when war is justified (jus ad bellum), how it should be conducted (jus in bello) and how a just peace can be restored after conflict (jus post bellum).

These ideas have had a significant influence on the way war is perceived and conducted, introducing the notion that even in war, certain actions are unacceptable and that the conduct of war must be governed by certain ethical and legal principles. The principles established by Grotius have continued to evolve and develop over the centuries, culminating in the formulation of more detailed and comprehensive international conventions, such as the Geneva Conventions, which govern behaviour in war today.

The organisation of the interstate system has led to the adoption of strict rules to regulate the conduct of war. The aim of these rules is to limit, as far as possible, the destructive consequences of war and to protect people who are not directly involved, such as civilians or prisoners of war. This is why, under international law, a war must be declared before it begins. The purpose of this declaration is to send a clear signal to all parties concerned, including other countries and international organisations, that an armed conflict has begun. During the war, combatants are bound by certain rules. For example, they must not deliberately target civilians, civilian buildings such as schools or hospitals, or use weapons prohibited by international law, such as chemical or biological weapons. Finally, after the war, a peace process must be put in place to resolve disputes, punish war crimes and repair the damage caused by the conflict. Although these rules are often violated, their existence and universal recognition are an important attempt to civilise an activity that is, by nature, violent and destructive.

War, despite its often devastating consequences, has been integrated into the interstate system as a means of resolving political disputes. It is important to note, however, that the idea is not to promote or glorify war, but rather to try to contain and regulate it. Since the 17th century, numerous rules have been established to try to limit the ravages of war. This includes international humanitarian law, which sets limits on how war can be waged, protecting people who are not or are no longer taking part in hostilities, such as civilians, health workers and prisoners of war. In addition, international law has also established rules on how to declare war, conduct hostilities and conclude peace. This includes the law of war, which establishes rules for the conduct of hostilities, and the law of peace, which regulates the conclusion of peace treaties and the resolution of international conflicts. These efforts to regulate war reflect the recognition that, although war may sometimes be unavoidable, it must be conducted in a manner that minimises human suffering and material destruction.[[Image:Helst, Peace of Münster.jpg|thumb|400px|<center>Banquet of the Amsterdam Civil Guard celebrating the Peace of Münster (1648), exhibited in the Rijksmuseum, by Bartholomeus van der Helst.]]

The Treaty of Westphalia, concluded in 1648 to put an end to the Thirty Years' War, was made up of two separate agreements: the Treaty of Osnabrück and the Treaty of Münster. The Treaty of Osnabrück was signed between the Swedish Empire and the Holy Roman Empire, while the Treaty of Münster was concluded between the Holy Roman Empire and the United Provinces (now the Netherlands) and between the Holy Roman Empire and France. These treaties are historically important because they laid the foundations for the modern international order based on the sovereignty of states. The principle of non-interference in the internal affairs of other states was established, as was the principle of checks and balances. The Treaty of Westphalia marked the end of the idea of a universal Christian empire in Europe and paved the way for a system of independent, sovereign nation states. 

The Treaties of Westphalia put an end to the Thirty Years' War, a religious war that tore Europe, and particularly the Holy Roman Empire, apart between 1618 and 1648. The war was fought mainly between Catholic and Protestant forces, although politics and the struggle for power also played an important role. By bringing the war to an end, the Treaties of Westphalia not only brought a welcome peace, but also marked a fundamental change in the political organisation of Europe. Before these treaties, the idea of a universal Christian empire, where a higher authority (either the Pope or the Holy Roman Emperor) would have some authority over kingdoms and principalities, was still alive. The Treaties of Westphalia established the principle of state sovereignty, asserting that each state had absolute and exclusive authority over its territory and its people. This meant that, for the first time, states, rather than emperors or popes, became the main players on the international stage. This is what is known as the "Westphalian system", which remains the foundation of modern international order.

Switzerland was recognised as an independent entity at the Treaty of Westphalia in 1648, although its current form as a state took longer to consolidate. Switzerland's perpetual neutrality was also established at the Congress of Vienna in 1815, reinforcing its distinct status on the international stage. Nevertheless, it should be noted that the Swiss Confederation as a union of cantons already existed before the Treaty of Westphalia. Its unique structure, however, did not correspond exactly to the concept of the nation state as it emerged with the Westphalian system. For this reason, Switzerland was slow to emerge in its modern form.

The Treaty of Westphalia laid the foundations for the modern international system based on national sovereignty. In other words, each state has the right to govern its territory as it sees fit without outside interference. This principle of non-interference in the internal affairs of other states is a key pillar of the international system. That said, it does not eliminate conflict or disagreement between states. When a dispute arises, war can be used as a means of resolution. However, in the modern world, other forms of conflict resolution, such as diplomacy, dialogue and negotiation, are generally preferred. War is often seen as a last resort when no other option is viable or effective.

The distinction between the internal and external space of states is fundamental to international politics. Within its borders, a state has the sovereignty to enforce its own laws and regulations, and to maintain order as it deems necessary. This internal space is often characterised by a set of well-defined rules and norms that are widely recognised and respected. Outside its borders, a state must navigate a more complex and often less regulated environment, where interactions take place primarily between sovereign states that may have divergent interests. This external space is governed by international law, which is less binding and more dependent on cooperation between states.

The principle of sovereignty, although it establishes the formal equality of all States in international law, does not necessarily translate into real equality on the international stage. Some states, because of their economic, military or strategic power, can exert a disproportionate influence. At the same time, the rise of non-state actors has made the international landscape more complex. Non-governmental organisations (NGOs), multinational corporations and even individuals (such as activists, political dissidents or celebrities) can now play significant roles in international politics. These actors can influence global policy by mobilising public opinion, taking direct action, providing essential services, or wielding economic power. However, despite the growing influence of these non-state actors, states remain the main and most powerful players on the international stage.

In the contemporary international system, the state is the fundamental political unit. The concept of the sovereign nation-state, although criticised and often complicated by issues of transnationalism, globalisation and interdependent international relations, remains the principal organiser of world politics. Each state, as a sovereign entity, is supposed to exercise absolute authority over its territory and population. The international system is based on the interaction of these sovereign states and on respect for the principles of non-interference in the internal affairs of other states. However, the reality is often more complex. Numerous non-state actors - from multinational corporations to terrorist groups, non-governmental organisations and international institutions - also play a major role on the international stage. At times, these actors may even challenge the authority and sovereignty of states. But despite these challenges, the idea of the nation state remains central to the understanding and structuring of our political world.

We don't talk about "world studies" or "global studies". The term that has come to the fore is "international relations". The field of study of "international relations" focuses on the interaction between states and, more broadly, between actors on the world stage. It is not simply a question of studying the world as a whole, but of understanding how states interact with each other, how they negotiate and contest power, and how they collaborate and enter into conflict. The emphasis is on 'relationships' because it is through these relationships that states define themselves in relation to each other, shape their foreign policy, and influence the international system. This is why, despite growing interdependence and globalisation, the notion of the nation state and the state boundary remain key concepts in the theory and practice of international relations. Indeed, the structuring of space between states is a fundamental dimension in the analysis of international relations. It is this structuring that determines alliances, conflicts, trade and population flows, among other things. It also has a significant influence on global governance and the development of international standards. 

The Treaty of Westphalia, signed in 1648, laid the foundations of modern international order based on the principle of national sovereignty. According to this principle, each state has the right to govern its own territory and population without outside interference. Sovereign equality means that, from the point of view of international law, all states are equal, regardless of their size, wealth or power. It means that every state has the right to participate fully in the international community and to be respected by other states.

That said, while the Treaty of Westphalia established sovereignty and sovereign equality as fundamental principles of the international system, it does not mean that war is an inevitable consequence of these principles. Indeed, although disputes between states can lead to armed conflict, war is neither the only nor the most desirable means of resolving disputes. The principles of international law, such as the peaceful settlement of disputes, are also central to the international order that emerged from Westphalia. Moreover, over the centuries, international norms and institutions have evolved to govern and regulate the conduct of war, and to promote dialogue, negotiation and cooperation between states. The Westphalian system is therefore not simply a licence for war, but the framework within which states coexist, collaborate and, at times, clash.

== From Total War to Institutionalised War (Holsti) ==
The 17th century was a period of significant transformation in the political and social organisation of many countries, leading to the emergence of the modern state. It was during this period that states began to consolidate their power, centralise authority, impose taxes systematically and develop more efficient and structured bureaucracies. This centralisation and bureaucratisation enabled states to amass resources and mobilise them more effectively, particularly with a view to waging war. As states became more powerful and efficient, they were able to wage war on a larger scale and with greater intensity. This paved the way for what is known as "total war", where all aspects of society are mobilised for the war effort and the distinction between combatants and non-combatants becomes blurred. Parallel to these changes, the international system was also evolving, with the establishment of the Westphalian system based on state sovereignty. These two processes - the evolution of the state and the transformation of the international system - were mutually reinforcing. The consolidation of the state contributed to the rise of the Westphalian system, while the latter provided a framework for states to develop and strengthen. 

While the modern state has greatly contributed to the reduction of interpersonal violence by establishing an internal social order and a monopoly on the legitimate use of force, its increased capacity to mobilise and concentrate resources has also led to the possibility of conflict on a larger scale, often with devastating consequences. In the context of international relations, the Westphalian system created an environment in which states, seeking to protect their interests and guarantee their security, could resort to war as a means of resolving their differences. This led to increasingly destructive wars, culminating in the two world wars of the twentieth century.

The evolution of norms and rules concerning war has led to a clearer distinction between combatants and non-combatants, with an effort to protect the latter from the direct effects of war. This idea has been codified in international humanitarian law, in particular in the Geneva Conventions. In the Middle Ages, the distinction between civilians and combatants was not always clear, and civilians were often directly affected by war. However, with the development of the modern state and the codification of warfare, a norm emerged that civilians should be spared as much as possible during conflicts. That said, although the distinction is now widely recognised and respected in theory, it is unfortunately often ignored in practice. Many contemporary conflicts have seen serious violations of this norm, with deliberate attacks on civilians and massive suffering for non-combatant populations.

From the 17th century onwards, with the rise of the nation-state and the professionalisation of armies, there was a reduction in the direct impact of war on civilians. Combatants - generally professional soldiers - became the main participants and victims of war. However, this trend was reversed during the 20th century, particularly with the two World Wars and other major conflicts, where civilians were often targeted or became collateral victims. This intensified after the end of the Cold War, with the rise of intra-state conflicts and non-state armed groups. In these conflicts, civilians are often directly targeted and make up the majority of victims.

The emergence of modern warfare is intrinsically linked to the emergence of the nation state. In the Middle Ages, conflicts were characterised by a fluidity of structures and factions, encompassing city-states, religious orders such as the papacy, warlords and other groups who frequently changed alliances according to their interests at the time. It was a time when violence was omnipresent, but the boundaries of conflict were often blurred and shifting. With the rise of the nation-state, the nature of warfare changed significantly. States began to raise armies of soldiers, identifiable by their uniforms, who served as representatives of the state on the battlefield. Whether these soldiers were paid professionals or conscripts mobilised for military service, they symbolised the state's ability and authority to project force and defend its interests. War thus became an extension of inter-state relations and state policies, with more clearly defined rules and conventions.

== From Total War to Institutionalised War (Holsti) ==
The Peace of Westphalia created a new political system, known as the Westphalian system, which formalised the idea of sovereign nation states. In this system, war became an institutionalised tool for resolving conflicts between states. Instead of being a series of chaotic and continuous skirmishes, war became a declared and recognised state of open conflict between sovereign states. This has also led to the emergence of rules and conventions of war, aimed at limiting the destructive effects of conflict and protecting the rights of combatants and civilians. These rules have been formalised in international treaties and conventions, such as the Geneva Conventions. 

K. J. Holsti, in his book "The State, War, and the State of War" (1996), distinguishes between two types of war. The "type 1 wars" he defines are the traditional wars between states, which were the norm from the Treaty of Westphalia until the end of the Cold War. These conflicts are generally clearly defined, with formal declarations of war, clear military fronts and the end of hostilities often marked by peace treaties. By contrast, "type 2 wars", according to Holsti, are modern wars, which tend to be much more chaotic and less clearly defined. They may involve non-state actors such as terrorist groups, militias or gangs. These conflicts can break out within state borders, rather than between different states, and they can last for decades, with constant violence rather than a clearly defined beginning and end.

The period between 1648 and 1789 is often referred to as the era of "limited war" or "cabinet war". These wars generally had clear and limited objectives. They were often fought for specific reasons, such as the control of particular territories or the resolution of specific disputes between states. These wars were usually fought by professional armies under the direct control of the state government, hence the term "cabinet war". The idea was to use war as a tool to achieve specific political objectives, rather than seeking the total destruction of the enemy. This corresponds to the Clausewitzian concept of war as "the continuation of politics by other means". These wars were generally well structured, with formal declarations of war, agreed rules of conduct and, ultimately, peace treaties to formally resolve the conflict. This reflects the level of formalisation and institutionalisation of the concept of war during this period. However, this began to change with the Revolutionary and Napoleonic wars of the late eighteenth and early nineteenth centuries, which were characterised by mass mobilisation and a much greater level of destruction. These wars paved the way for the era of "total wars" in the twentieth century.

This period of history, generally between the Treaty of Westphalia in 1648 and the French Revolution in 1789, saw a major codification of military structures and the rules of war. The appearance of distinctive uniforms is a sign of this codification. Uniforms helped to clearly identify belligerents on the battlefield, contributing to a measure of discipline and order. This period also saw the rise of what might be called a professional "military culture". Armies of this period were often commanded by members of the nobility, who were trained in the art of warfare and saw military service as an extension of their social and political obligations. It was often during this period that we see the emergence of the "noblesse d'épée", a class of nobility who derived their status and reputation from their service in the army. At the same time, the rules of war were codified, leading to greater attention being paid to the rights of prisoners of war, diplomatic immunity and other aspects of the law of war. These codes of conduct were reinforced by international treaties and conventions, laying the foundations for modern international law.

During this period of history, wars were generally characterised by limited objectives and relatively short engagements. Belligerents often sought to achieve specific strategic objectives, such as the capture of a particular territory or fortress, rather than the total destruction of the enemy. These conflicts were often characterised by 'manoeuvre warfare', where armies sought to gain strategic advantage through movement and position rather than frontal combat. Battles were often the exception rather than the rule, and many conflicts ended in negotiation rather than total military victory. This way of waging war was partly a consequence of the logistical constraints of the time. Armies were often limited by their ability to supply their troops with food, water and ammunition, which restricted the duration and scale of military engagements.

During this period of limited warfare, the objective was not the total annihilation of the opponent, but rather the achievement of specific strategic goals. Battles were often carefully orchestrated and armies sought to minimise unnecessary loss of life. The emphasis was on strategy and tactics, not indiscriminate destruction. Civilians were generally spared, partly because war was seen as an affair between states, not between peoples. However, this is not to say that civilians were never affected. The disruption caused by war could lead to famine, epidemics and other forms of suffering for civilian populations.

The War of the Spanish Succession (1701-1714) is a good example of a war of this period. It was triggered by the death of King Charles II of Spain without a direct heir. The conflict pitted the major European powers against each other as they sought to control the succession to the Spanish throne and, by extension, to increase their influence and power in Europe. The war was limited in time, and although it was brutal and costly in terms of human lives, it was governed by accepted rules and conventions that limited its intensity and scope. For example, battles were generally fought by regular armies, and civilians were largely spared. However, this war was significant in terms of geopolitical change. It saw the rise of Great Britain and marked a turning point in the balance of power in Europe. It also led to the Treaty of Utrecht in 1713, which redefined borders and had a lasting impact on European politics.

The period from the end of the 17th century to the 18th century was marked by the gradual codification of armies. This codification covered many aspects of military conduct. The structure of armies began to be formalised with the introduction of clearly defined hierarchies and specific military roles. This led to better organisation and coordination of the armed forces. The codification of uniforms was another major aspect. Military uniforms not only distinguished soldiers from civilians, but also made it possible to distinguish allies from enemies and to identify the rank and role of each soldier. Conduct on the battlefield was also regulated. Specific rules were established to govern actions in wartime, including the treatment of prisoners of war and conduct towards civilians. This codification of armies was an essential part of the formation of modern nation states. It has led to greater efficiency and better organisation in the conduct of war, while limiting certain forms of violence and protecting non-combatants to a certain extent.

The military uniform played a crucial role in the identification and organisation of the armed forces during this period. It served multiple important functions. Firstly, identification. Uniforms helped to distinguish allies from adversaries on the battlefield. They also served to identify an individual's rank and function within the army. This is one way of creating clarity during conflicts, where situations can be chaotic and changeable. Secondly, the uniform creates a sense of unity among soldiers. By wearing the same set of clothes, soldiers feel linked to each other, sharing a common identity. The uniform symbolises their loyalty to the state and their commitment to the cause they are fighting for. Secondly, the uniform promotes discipline and order. By imposing uniform dress, the army reinforces its hierarchical and structured organisation. It is a constant reminder of the rigour and structure that military life requires. Finally, the uniform is also a tool for representing the power and prestige of the State. It is often designed to impress or intimidate opponents. It is a visual statement of the state's strength and potential. The standardisation of military dress began to occur from the 17th century onwards, in parallel with the development of the modern state and standing armies. This process was influenced by technological advances that made mass production of clothing possible, as well as by the need for greater discipline and organisation within the armed forces.

== The Second Type of War or Total War: 1789 - 1815 and 1914 - 1945 ==

[[File:Charles Meynier - Napoleon in Berlin.png|thumb|''Napoleon in Berlin'' (Meynier). After defeating Prussian forces at Jena, the French Army entered Berlin on 27 October 1806.]]

Continuing K.J. Holsti's typology, wars of the second type emerged with the wars of the Revolution and Empire at the beginning of the 19th century. These conflicts differed considerably from the first type of wars of the seventeenth and eighteenth centuries. 

Wars of the second type, also known as mass wars or Napoleonic wars, were characterised by an unprecedented mobilisation of human and material resources. They are defined by a desire to annihilate the enemy, unlike wars of the first type, which were primarily aimed at achieving limited political objectives. These wars are often longer, more costly and more destructive. Conflicts are no longer confined to one-off, limited battles, but extend to large-scale military campaigns. What's more, the distinction between combatants and civilians became blurred, with entire populations involved in the war effort, whether through conscription or support for the war effort. The Napoleonic Wars are a classic example of this type of war, with millions of people mobilised across Europe, a series of conflicts lasting over a decade, and major political and territorial changes as a result.

The French Revolution of 1789 marked a major turning point in the way wars were fought. With the emergence of the revolutionary ideas of liberty, equality and fraternity, war became more than just an instrument of state policy. It became an expression of the nation's collective aspirations and ambitions. The notion of a "nation in arms" appeared for the first time during this period. This concept was part of the idea of a total mobilisation of the population in preparation for war. It was no longer simply a question of war professionals or mercenaries fighting, but of the entire population, including ordinary citizens. These citizens are called upon to take up arms not only to defend their territory, but also to defend the very idea of the nation and the principles on which it is based. This was made possible by the levée en masse, a revolutionary measure that conscripted large numbers of citizens into the army. This measure enabled France to mobilise considerable human resources to face the threat of the European powers aligned against it. The consequence of this new approach to warfare was an unprecedented escalation of violence and destruction, and the growing involvement of civilians in the conflict. This trend was to continue and intensify over the next two centuries, notably with the two world wars of the 20th century.

The French Revolution overturned the established order in Europe. The traditional monarchies, threatened by the revolutionary ideas of popular sovereignty and democracy, formed coalitions to try to restore the Ancien Régime in France. In response to these external threats, the French revolutionary leaders decided to raise a large army of citizens. This was a major break with the past, when armies were made up mainly of mercenaries or professional troops. The Levée en masse decree, adopted in 1793, mobilised all French citizens of military age. The aim was to repel the armies of the European monarchies that were invading France. This mass mobilisation led to the formation of an army of several hundred thousand soldiers, who ultimately succeeded in repelling the invasions and preserving the Revolution. This mass mobilisation is considered to be the first national mobilisation in modern history. It transformed the nature of war from a limited conflict between professional warriors to a struggle involving the whole nation. It also changed the relationship between citizens and the state, as their role was no longer simply to obey, but also to actively defend the nation and its ideals. 

The transition to a conscript army required a modern, organised state capable of taking a census of its population, rapidly training and equipping thousands of soldiers, and sustaining the war effort over the long term. Mass mobilisation transformed the nature of warfare by making it possible to mobilise very large armies. Under Napoleon, for example, the French army grew to over 600,000 men, an unprecedented figure for the time. This also increased the army's capacity to conduct operations on several fronts at once. However, it also increased the complexity of military logistics, requiring the supply of food, weapons and ammunition for many more soldiers. It has therefore required a more efficient and organised state, capable of planning and supporting these large-scale operations. It also led to a change in the nature of war itself. With such large armies, battles became more destructive and resulted in more casualties. War became an affair of entire nations, involving not only the soldiers, but also the civilians who supported the war effort in the rear.

The introduction of a conscript army requires a modern state, for several reasons. Firstly, a modern state has an efficient administration. This administration is needed to identify the population and manage conscription. Identifying, registering, mobilising and training recruits is an enormous administrative task that requires an efficient bureaucracy. Secondly, the state must have the logistical capacity to support a large army. This means that it must be able to supply food, clothing, weapons and ammunition to a large number of soldiers. It must also have the capacity to care for the wounded. All these tasks require a solid logistical infrastructure. Thirdly, a modern state generally has an economy strong enough to support a conscript army. Wars are expensive, and you need a state that is capable of financing these expenses. Finally, mass mobilisation requires a degree of social cohesion and solidarity. The state must have the legitimacy to ask its citizens to fight and die for it. This is generally easier in a nation-state, where citizens share a common sense of belonging. Finally, the move to a conscript army is a manifestation of the modernity of a state, illustrating its ability to exercise power over its citizens and mobilise its resources to achieve its objectives.

The second type of war, according to Holsti's typology, is characterised by large-scale conscript armies, and no longer by professional armies based on mercenaries. These wars emerged after the French Revolution and reached their apogee with the Napoleonic Wars. The underlying idea is that the entire nation, rather than a warrior caste or professional elite, is mobilised for war. Soldiers were no longer fighting for pay, but for the defence of the nation and its values. This is a major transformation in the nature of warfare, involving a much greater degree of commitment and sacrifice on the part of citizens. This new form of warfare made it possible to raise much larger and more powerful armies than in the past, which contributed to Napoleon's domination of Europe. In addition, these nationalist armies changed the way in which war was perceived and experienced by the population. War was no longer a professional affair, but a cause for which every citizen was prepared to give his or her life. This also had a significant impact on the nature of conflicts and the scale of destruction and loss of life they could cause.

The ideological nature of revolutionary wars leads to an intensification of conflict. Unlike so-called "traditional" wars, where the objectives are often territorial or material, revolutionary wars tend to have more abstract and fundamental objectives. It is no longer simply a question of winning territory or appropriating resources, but of defending an idea, an ideal, or even an identity. In this context, the enemy is not just a military adversary, but also a threat to the very existence of the nation and its values. Consequently, the aim is not just to defeat the enemy on the battlefield, but to annihilate him completely, because his mere existence is perceived as a threat. This can lead to an escalation of violence and to particularly deadly and destructive wars. The fact that the entire population is mobilised for war also contributes to the intensification of conflicts, as everyone feels personally involved and ready to make sacrifices for the cause. On the other hand, these wars can also be perceived as more legitimate or justified by those who wage them, because they are fighting for a cause in which they deeply believe, and not simply for power or profit. This can help to strengthen national unity and the determination to fight.

In wars of the second type, such as revolutionary wars, the nature of the objectives changes significantly compared to more traditional conflicts. The objectives are no longer purely material, such as the capture of territory or the control of resources, but become ideological and abstract. These objectives, such as "liberation", "democracy" or "class struggle", are not only open-ended, but also vague and subjective. They cannot be measured or achieved in concrete terms, which can make the end of the conflict difficult to define or achieve. Moreover, these more abstract objectives can also lead to more intense and prolonged conflicts. Because these objectives are often perceived as essential to a nation's identity or survival, combatants are often prepared to go further and take greater risks to achieve them. Finally, these ideological objectives can also make it more difficult to reach a peace agreement. As these objectives are often absolute and non-negotiable, they often require the unconditional surrender of the adversary, which can make negotiations more complicated and prolong the duration of conflicts.

The Second World War is a perfect illustration of the notion of a "war of the second kind". The main objective was not only to defeat Nazi Germany militarily, but also to eliminate Nazi ideology itself. This war was not simply a question of territory or resources, but an ideological struggle. The aim was not a traditional surrender, where enemy forces lay down their arms and return home. On the contrary, the aim was the total eradication of Nazism as a political and ideological system. This led to demands for "unconditional surrender" from the Allies, meaning that the Nazis had no opportunity to negotiate the terms of their surrender. This was an unusual demand in the historical context of conflicts, illustrating the exceptional and total nature of this war. In addition, after the end of the war, Germany was occupied and divided, and a process of "denazification" was undertaken to eliminate Nazi influence from German society. This demonstrated the extent of the Allies' commitment to eliminating not only the Nazi military threat, but also the Nazi ideology itself. 

The transition to this type of total war was closely linked to the evolution of the state. With the emergence of the modern nation-state and nationalism in the eighteenth and nineteenth centuries, war increasingly became a matter for all the people, not just the army. In the total wars of the twentieth century, such as the two world wars, all aspects of society and the economy were mobilised for the war effort. Civilians became war targets, either directly through bombing or indirectly through blockades and famine. Moreover, the raison d'être of these wars was often expressed in ideological or existential terms, such as the defence of democracy against fascism, or the fight for the survival of the nation. In this context, a simple victory on the battlefield was not enough - the enemy had to be completely defeated and its political and ideological system dismantled.

The Nazi regime was able to come to power and commit its atrocities on such a massive scale largely because of the infrastructure and apparatus of the state in Germany at the time. Modern state structures, including highly centralised bureaucratic, military and economic institutions, can potentially be hijacked for nefarious purposes, as was the case with Nazism in Germany. Without such a powerful and well-organised state, it would have been much more difficult, if not impossible, for totalitarian ideologies such as Nazism to implement their destructive plans on such a massive scale. Similarly, without the industrial and military power of a modern state, the Nazi regime would not have been able to launch a war on a global scale.

The Second World War marked a significant break in the way war was waged, particularly in terms of targets. With the spread of aerial bombardment and the industrialisation of warfare, civilians became direct targets. This war saw the majority of casualties shift from soldiers to civilians. In this context, weapons of mass destruction, such as atomic bombs, can cause massive destruction and the death of thousands, even hundreds of thousands, of civilians in an instant. Moreover, the war effort involves the entire population, and the arms industry is often a priority objective, leading to an increase in the number of civilian casualties. The second type of war also saw the implementation of genocidal policies and large-scale crimes against humanity, requiring industrial resources and state organisation. The Nazi concentration and extermination camps are a tragic example of how industrial capacity and state bureaucracy can be used for inhuman purposes. All this illustrates once again the extent to which the modern state and its capacity to organise and mobilise resources can have dramatic consequences when misused. 

The history of the 20th century clearly shows that war and industrialisation are intrinsically linked. During the two World Wars, nations had to rapidly transform their economies to support the war effort, leading to a significant acceleration in industrialisation. Factories that had previously been dedicated to the production of consumer goods were converted to produce weapons, military vehicles, munitions and other war materials. These industries had to be modernised and rationalised to achieve an unprecedented level of production, which encouraged the development of new technologies and production techniques. During the First World War, for example, the production of steel and other essential materials increased exponentially to meet the needs of the war. This increased production capacity was then reused after the war to stimulate economic growth.

From the end of the 18th century, with the emergence of the revolutionary and Napoleonic wars, we witnessed a major transformation in the nature of conflicts. These wars of the second type became total wars, involving not only armies but the whole of society. In these total wars, mobilising the population becomes essential. States set up conscription systems to recruit large numbers of soldiers, transforming war into a truly national effort. Every country's economic, industrial and technological resources were mobilised to support the war effort. This meant that the whole of society was affected by the war. Civilians are directly involved, whether as combatants on the front line, as workers in the armaments factories, or as logistical support in the communications, transport and health infrastructures. Civilians also suffer the consequences of war, including material destruction, forced displacement, deprivation and loss of life. These total wars profoundly affect the lives of the societies involved. They strengthened the link between the State and the population, transforming war into a collective and national commitment. The distinction between front and rear became blurred, and war became an omnipresent reality in the daily lives of civilians.

Between 1815 and 1914, there was a period of relative stability and peace in Europe, often referred to as the "Hundred Years' Peace" or the "Long 19th Century". During this period, the major European powers avoided major conflicts between themselves, which led to a degree of political, economic and social stability on the continent. However, this period of relative peace was not without its more limited tensions and conflicts. Regional wars and crises, colonial conflicts and struggles for national independence erupted during this period. In addition, rivalries and tensions between European powers built up over time, particularly as a result of imperialism, colonial rivalries and nationalist tensions. The apparent stability of this period was shattered by the outbreak of the First World War in 1914. This major conflict was a turning point in history and marked the end of relative peace in Europe. It was followed by a series of major political, social and economic upheavals that marked the 20th century.

After the Napoleonic Wars, the Congress of Vienna was held in 1814-1815. It brought together the main European powers of the time with the aim of reorganising Europe after the upheaval caused by the Napoleonic Wars and preventing new conflicts. The Congress of Vienna established the principle of the "Concert of Nations", also known as the "Vienna System". This was a system of multilateral diplomacy in which the major European powers met regularly to discuss international issues and maintain peace in Europe. The idea was to create a balance of power and avoid the destructive wars that had characterised the Napoleonic period. The Concert of Nations was an attempt to establish a system of international relations based on cooperation, consultation and diplomacy. However, despite its efforts, the system showed its limitations over time, particularly when it came to dealing with the political changes and nationalist aspirations that emerged during the 19th century. The period following the Congress of Vienna was marked by tensions and conflicts, including the rise of nationalism, the revolutions of 1848 and colonial rivalries. These developments eventually led to the end of the "Hundred Years' Peace" and the outbreak of the First World War in 1914.

The Concert of Nations, also known as the Metternich System, was established after the fall of Napoleon in 1815 at the Congress of Vienna. The winners of the war against Napoleon - Great Britain, Austria, Prussia and Russia, the main powers at the time - defined new rules for managing international relations. These rules established a concerted system for managing disputes between states, based on the balance of power, respect for treaties and non-interference in the internal affairs of other states. The idea was to avoid a recurrence of the devastating wars that had marked the Napoleonic era. As a result, although it was not a fully-fledged collective security system, the Concert of Nations fostered cooperation between the powers and helped to maintain stability in Europe for much of the 19th century. Indeed, the system worked relatively well for a time, with a notable reduction in the number of major wars in Europe. However, it was also criticised for supporting and reinforcing the status quo, thereby impeding social and political progress. Moreover, it ultimately failed to prevent the outbreak of world wars in the 20th century. The Concert of Nations was a milestone in the history of international relations, laying the foundations for modern multilateral diplomacy and serving as a precursor to international organisations such as the League of Nations and the United Nations.

== The post-1945 era ==
Although there were considerable tensions during the Cold War, particularly between the Soviet Union and the United States, Europe has enjoyed an unprecedented period of peace since 1945. This period, often referred to as the "Pax Europaea" or European Peace, marked the longest period of peace on the continent in modern history. After the Napoleonic Wars, Europe experienced a relatively peaceful period known as the "Hundred Years' Peace" between 1815 and 1914, despite some notable conflicts such as the Crimean War and the Franco-Prussian War. This period was marked by the general stability provided by the Concert of Nations, which promoted the balance of power and the diplomatic resolution of conflicts. Similarly, despite the tensions of the Cold War and the threat of nuclear destruction after 1945, Europe enjoyed an extraordinarily long period of peace. This 'Pax Europaea' can be attributed to a number of factors, including nuclear deterrence, the creation and expansion of the European Union, the presence of NATO forces and the Warsaw Pact, and the substantial economic aid provided by the Marshall Plan. These elements have contributed to an increased interdependence between European nations, making direct conflict not only undesirable, but increasingly unthinkable. As a result, despite the challenges and tensions of the post-war world, Europe has been able to maintain a lasting and meaningful peace. 

Until the recent conflicts in Ukraine, peace in Europe was largely maintained. The conflict in Ukraine, which began in 2014, represents a significant break in that peace. However, it is important to note that this conflict is more localised and has not resulted in a large-scale war involving many European countries, as was the case in the two world wars. The Ukrainian crisis has highlighted some of the tensions that still exist in Europe, particularly between Russia and Western nations. The situation in Ukraine is complex and has raised many challenges for stability and security in Europe. It has called into question the effectiveness of some of the structures and agreements that have helped to keep the peace in Europe for decades. Nevertheless, even with the conflict in Ukraine, the period since 1945 remains one of the most peaceful in European history, particularly in comparison with previous centuries which were marked by frequent and devastating wars.[[File:United Nations General Assembly Hall (3).jpg|thumb|left|267px|United Nations General Assembly hall.]]

While Europe and other parts of the developed world have enjoyed a period of relative peace since the Second World War, many other places suffered violent conflict during the Cold War and beyond. This period was marked by a number of proxy wars, where the major powers supported opposing parties in local conflicts without engaging directly in war. Examples of these proxy wars include the Korean War, the Vietnam War, the Angolan Civil War, and the wars in Afghanistan, among others. These conflicts have often resulted in heavy civilian casualties and have had long-term impacts on the stability and development of the regions concerned. It is an important reminder that, while the "Pax Europaea" and peace between the great powers are important, they do not represent the entire history of war and peace in the twentieth century and beyond. Conflicts continue to affect many parts of the world, often with devastating consequences for local populations. 

Historically, major conflicts were often the result of direct wars between great powers. However, since the end of the Second World War in 1945, these powers have largely avoided engaging in direct conflict with each other. This transition can be attributed to several factors. The development and proliferation of nuclear weapons has created a mutual deterrent, where the cost of direct conflict would be total destruction. In addition, increasing economic interdependence has made war less attractive to the great powers, as it would disrupt world trade and financial markets. In addition, the creation of international institutions such as the United Nations has provided mechanisms for the peaceful resolution of disputes. Finally, the spread of democracy may also have contributed to this trend, as democracies tend to avoid waging war against each other, a concept known as "democratic peace".

Since the end of the First World War, there has been a growing trend towards the idea of war as illegal or, at any rate, something to be avoided. This is a major change in the way war has been perceived historically. The creation of the League of Nations after the First World War was a first step towards this idea. Although the League of Nations failed to prevent the Second World War, its successor, the United Nations, was founded on similar principles of peaceful resolution of disputes and prevention of war. In addition, the evolution of international humanitarian law and the Geneva Conventions established certain rules on the conduct of war, with the idea of minimising its harmful effects. More recently, the idea of the "Responsibility to Protect" (R2P) has been developed to justify international intervention in situations where a state is unable or unwilling to protect its own population.

The philosopher Immanuel Kant sketched out a plan for "perpetual peace" in a treatise he published in 1795. Kant formulated the idea that liberal democracies are less likely to go to war with each other, a theory that was taken up by other political thinkers and became known as "democratic peace". According to this theory, democracies are less prone to war because their governments are accountable to their citizens, who bear the human and economic costs of conflict. Kant also promoted the idea of a federation of free nations, a sort of forerunner of today's international organisations such as the United Nations. The aim of this "federation of peace" would be to resolve conflicts through negotiation and international law rather than war.

After the end of the Second World War in 1945, the nations of the world sought to establish structures to maintain peace and prevent future conflicts. This led to the creation of the United Nations Organisation (UNO), which aims to facilitate international cooperation and prevent conflict. The UN is an example of what is known as a collective security system. In such a system, states undertake to cooperate to ensure the security of all. If one state attacks another, the other states are expected to side with the attacked state and take action to deter or stop the aggressor. In addition to the UN, other organisations and treaties have also been established to promote collective security, such as the North Atlantic Treaty Organisation (NATO) and the European Union. These mechanisms have helped to prevent major conflicts between major powers since 1945. However, they also have their limits and are not always effective in preventing conflicts, as can be seen from the many regional conflicts and civil wars that have taken place since 1945.

The United Nations Charter, established in 1945, laid down essential rules to regulate the use of force between states. In general, it prohibits the use of force in international relations, except under two specific circumstances. Firstly, Article 51 of the Charter enshrines the inherent right of States to individual or collective self-defence in the event of an armed attack. This means that a State is entitled to defend itself if it, or another State with which it has concluded a defence agreement, is attacked. Secondly, Chapter VII of the Charter allows the UN Security Council to take measures to preserve or restore international peace and security. This can include the use of force and has been the basis for the authorisation of several military interventions, such as the Gulf War in 1991. Although these principles were designed to limit the use of force and encourage the peaceful resolution of conflicts, they have also been controversial, particularly with regard to their interpretation and application in concrete situations.

Since 1945, there has been a growing trend towards the regulation and prohibition of war. The United Nations Charter was an important milestone in this development, prohibiting the use of force in international relations except in self-defence or with the authorisation of the Security Council. In addition to the UN Charter, other treaties and conventions have also contributed to this trend. For example, the Geneva Conventions and their Additional Protocols have established strict rules for the conduct of war, with the aim of limiting human suffering. Similarly, arms control treaties, such as the Treaty on the Non-Proliferation of Nuclear Weapons, have sought to limit the proliferation of the most destructive weapons. At the same time, there has been a growing movement towards the peaceful resolution of conflicts. Peaceful dispute resolution mechanisms, such as mediation, arbitration and judicial settlement, are increasingly used to resolve international disputes. However, although these efforts have helped to limit and regulate war, they have not succeeded in eliminating it completely. Conflicts continue to occur in many parts of the world, underlining the persistent challenge of achieving lasting and universal peace.

= The contemporary transformation of war =
The end of the Cold War in 1989, marked by the fall of the Berlin Wall, represented a major turning point in the history of modern warfare. During this period of bipolar tension between East and West, the world had been divided between the two superpowers, the United States and the Soviet Union. Although these two superpowers were never in direct conflict, they supported proxy wars around the world, leading to protracted and costly conflicts. The end of the Cold War changed the dynamics of modern warfare in several ways. Firstly, it signalled the end of the bipolarity that had characterised world politics for almost half a century. As a result, the nature of conflict changed, from wars between states to civil wars and non-state conflicts. Secondly, the end of the Cold War also ushered in a new wave of optimism about the possibility of lasting world peace. There was hope that, without the constant tension of the Cold War, the world could make significant progress towards resolving conflicts and preventing war. Finally, the end of the Cold War also led to a number of new challenges, including the proliferation of nuclear weapons, the rise of international terrorism and the growing problem of failed states. These challenges have influenced the nature of modern warfare and continue to be major issues for global security.

The end of the Cold War in 1989 marked a significant turning point in world history, with profound implications for the nature of warfare and the modern state. Until then, the evolution of modern warfare was closely linked to the emergence and consolidation of the modern nation state. This state was characterised by clearly defined territorial sovereignty, a monopoly on legitimate violence and a centralised governance structure. Wars were mainly confrontations between these nation-states. However, after 1989, many researchers observed a significant change in this dynamic. Wars became less frequently direct confrontations between nation-states, and more often internal conflicts, civil wars, or wars involving non-state actors such as terrorist groups or militias. What's more, the very notion of state sovereignty has begun to be called into question. Humanitarian interventions, peacekeeping operations and the doctrine of the "responsibility to protect" have all challenged the traditional idea of non-interference in a state's internal affairs. It can therefore be said that the end of the Cold War ushered in a new era in which the relationship between war and the state is changing. The precise contours of this new era are still the subject of debate among scholars and analysts.

Since the end of the Cold War, many researchers and military experts suggest that warfare has undergone a significant transformation. These transformations have been attributed to a variety of factors, including developments in military technology, globalisation, changes in the nature of the state and the relative decline of interstate warfare. Today's wars are often described as 'postmodern', to reflect their difference from the traditional wars of previous centuries. Post-modern wars are often characterised by their complexity, involving a multitude of state and non-state actors, and sometimes even private companies and non-governmental organisations. They often take place in urban environments, rather than on traditional battlefields, and may involve asymmetric actors, such as terrorist groups or cyber-attackers. These post-modern wars have also challenged the traditional norms and rules of warfare. For example, how can the principles of international humanitarian law, designed for wars between states, be applied to conflicts involving non-state actors or cyber attacks? This does not mean that the old forms of warfare have completely disappeared. There are still conflicts that resemble traditional wars. However, these new forms of conflict have added a layer of complexity to the art of warfare, requiring constant reflection and adaptation to the new realities of the 21st century.

== The New World (Dis)Order ==

The fall of the Berlin Wall in 1989 and the dissolution of the Soviet Union in 1991 marked the end of the Cold War and the bipolar system that had dominated world politics for almost half a century. During this period, the United States and the Soviet Union, as superpowers, had established two distinct blocs of global influence. Despite constant tensions and numerous crises, open conflict between these two powers was avoided, largely because of the threat of Mutually Assured Destruction (MAD) in the event of nuclear war. However, the end of the Cold War has not led to a "new world order" of peace and stability as some had hoped. Instead, new challenges and conflicts have emerged. Failed states, civil wars, international terrorism and the proliferation of weapons of mass destruction have become major problems. The nature of conflicts has also changed, with an increase in asymmetric warfare and conflicts involving non-state actors. 

The end of the Cold War ushered in a new era in world politics, marked by a certain amount of optimism. Many experts and policy-makers hoped that the end of superpower rivalry would lead to an era of greater international peace and cooperation. The political philosopher Francis Fukuyama even described this period as "the end of history", suggesting that liberal democracy had finally emerged as the undisputed and definitive system of government. With the demise of the Soviet Union, the United States found itself as the world's sole superpower, ushering in what some have called the American 'hyperpower'. Many believed that this new unipolar era would bring greater stability and peace to the world. At the same time, the end of the rivalry between the two superpowers enabled the United Nations to play a more effective role in preventing conflict and promoting peace. The systematic obstruction by one of the permanent members of the UN Security Council, which had often paralysed the organisation during the Cold War, has largely been lifted. This led to a significant increase in UN peacekeeping operations during the 1990s.

With the end of the Cold War, the 1990s saw a significant increase in UN peacekeeping operations. UN peacekeepers were deployed to conflicts around the world, with the aim of maintaining or restoring peace and promoting reconciliation and reconstruction. The idea was that these peacekeeping operations could help prevent the escalation of conflicts, protect civilians, facilitate the delivery of humanitarian aid and support the peace process. In other words, these missions were supposed to help "reap the peace dividend" after the end of the Cold War.

The end of the Cold War and the emergence of a new international system have been accompanied by a growing discourse on "global disorder". This term refers to the idea that the post-Cold War world is characterised by increased uncertainty, complex and interconnected global challenges, and the absence of a clear and stable framework for international governance. Several factors have contributed to this perception of "global disorder". Firstly, the end of the bipolarity of the Cold War eliminated the clear framework that had previously structured international relations. Instead of a world divided between two superpowers, we have witnessed a more complex, multipolar landscape with many important players, including not only nation states, but also international organisations, multinational corporations, non-governmental groups and others. Second, the post-Cold War world has been marked by a series of global challenges, including transnational terrorism, financial crises, climate change, pandemics, cyber security, and other problems that do not respect national borders and cannot be solved by a single country or even a group of countries. Finally, there has been a growing awareness of the limitations and contradictions of existing international institutions. For example, the UN, the IMF, the World Bank and other organisations have been criticised for their lack of representativeness, their inefficiency and their inability to respond effectively to global challenges. Against this backdrop, the question of how to manage this 'global mess' and build a fairer, more efficient and resilient international system has become a central issue in world politics.

In his much-discussed book "The Clash of Civilisations", political analyst Samuel P. Huntington proposed a new way of looking at the post-Cold War world. He argued that future sources of international conflict would involve not so much political or economic ideologies, but rather the differences between the world's various great civilisations. According to Huntington, the world could be divided into around eight major civilisations, based on religion and culture. He predicted that the greatest conflicts of the 21st century would be between these civilisations, particularly between Western civilisation and the Islamic and Confucian civilisations (the latter represented mainly by China).

The end of the Cold War marked a significant transition in the nature of conflict. Whereas the Cold War period was dominated by interstate conflicts and proxy wars between the two superpowers, the post-Cold War era has seen a significant increase in civil wars and internal conflicts. These conflicts have often involved a variety of non-state actors, such as rebel groups, militias, terrorist groups and criminal gangs. In addition, they have often been marked by intense and prolonged violence, massive human rights violations and severe humanitarian crises. These trends have posed serious challenges for the international community. On the one hand, it has been more difficult to manage and resolve these conflicts, as they often involve deep-rooted issues such as ethnic or religious identity, governance, inequality and access to resources. Furthermore, these conflicts often have destabilising effects that transcend national borders, such as refugee flows, the spread of extremist groups, and regional destabilisation.

Historically, the nation-state was the main actor in armed conflicts, and most wars were fought between states. However, with the collapse of the bipolar world order at the end of the Cold War, the nature of war began to change. Civil war, once a relatively rare type of conflict, became increasingly common. These internal conflicts often involved a variety of non-state actors, such as rebel groups, militias, terrorist groups and criminal gangs. The rise of civil wars has posed new challenges for conflict management and international security. Unlike inter-state wars, civil wars are often more complex and difficult to resolve. They can involve deep-rooted problems such as ethnic or religious divisions, governance, inequality and access to resources. Moreover, these conflicts often have destabilising consequences that transcend national borders, such as refugee flows, the spread of extremist groups and regional destabilisation.

Since the end of the Cold War in 1989, the nature of conflicts has changed significantly. Whereas inter-state wars were once the dominant form of conflict, the post-Cold War era has seen an increase in civil wars and internal conflicts. These civil wars have often involved a range of non-state actors, including armed groups, militias, terrorist groups and gangs. As a result, there is often a perception that the state is no longer the main actor in armed conflicts. This represents a significant challenge for the international system, which was built on the principle of state sovereignty and designed to manage conflicts between states. Civil wars are often more complex, more difficult to resolve and more likely to cause humanitarian crises than wars between states.

The post-Cold War era has been marked by the emergence and proliferation of a variety of non-state actors who have become key players in many conflicts around the world. Terrorist groups, militias and criminal organisations such as mafias and gangs have become major players in violence and conflict. These actors have often succeeded in exploiting the weaknesses of the state, particularly in countries where the state is weak or fragile, where it lacks the capacity to effectively control its territory or provide basic services to its population. They have often used violence to achieve their aims, whether to undermine the authority of the state, to control territory or resources, or to advance a political or ideological cause. This has had many implications for international security. On the one hand, it has made conflicts more complex and more difficult to resolve. On the other, it has led to increased violence and instability, with devastating consequences for civilian populations.

The concept of sovereignty, which has long been fundamental to structuring the inter-state system and regulating violence, has been seriously challenged in the post-Cold War context. The rise of violent non-state actors, such as terrorist groups and criminal organisations, has often taken place in areas where state authority is weak or absent, highlighting the limits of sovereignty as a means of maintaining order and security. In addition, the proliferation of internal conflicts and civil wars has raised important questions about the responsibility of the state to protect its own population and the right of the international community to intervene in the affairs of a sovereign state to prevent or end serious human rights violations. These challenges have led to important discussions and debates on the nature and meaning of sovereignty in the 21st century. Among the concepts that have emerged from these debates is the principle of the "responsibility to protect", which states that sovereignty is not only a right, but also a responsibility, and that if a state is unable or unwilling to protect its population from mass crimes, the international community has a responsibility to intervene.

Failed states' are states that can no longer maintain order and security throughout their territory, provide essential services to their people or represent legitimate power in the eyes of their citizens. These states, although still recognised as sovereign on the international stage, are often faced with a loss of control over a significant part of their territory, insurgencies or violent internal conflicts, as well as corruption and poor governance. Since the 1990s, a large number of conflicts, particularly in Africa but also in other parts of the world, have taken place in these failed states. These conflicts are often characterised by massive violence against civilians, widespread violations of human rights and international humanitarian law, and often have a destabilising impact on surrounding countries and regions.

The increase in internal conflicts and civil wars since the 1990s has prompted a re-evaluation of the traditional concept of sovereignty in international discourse. Whereas sovereignty had previously been seen as a guarantee of order and stability, protecting states from external interference, it began to be perceived in a more problematic light. In this context, sovereignty was sometimes seen as a barrier to international intervention in situations where populations were threatened by mass violence, genocide or crimes against humanity. This has given rise to debates about the "responsibility to protect" and when and how the international community should intervene to protect civilian populations, even in violation of the traditional principle of non-interference in the internal affairs of a sovereign state. Moreover, sovereignty has also been called into question as a source of legitimacy, when authoritarian or despotic regimes have used it to justify human rights violations or to resist demands for democratic reform. Thus, although sovereignty remains a fundamental principle of the international system, its meaning and application have become increasingly contested in the contemporary context.

== The Emergence of New Wars ==

Mary Kaldor, a specialist in international relations and war theory, introduced the idea of 'new wars' in her book New and Old Wars: Organised violence in a global era (1999). In her view, the conflicts that have emerged since the end of the Cold War have distinct characteristics from the traditional 'old wars', largely due to the impact of globalisation and political, economic and technological change. 

The 'new wars', according to Kaldor, are typically characterised by:

* The degradation of war into diffuse and often decentralised violence, involving a variety of non-state actors, such as militias, terrorist groups, criminal gangs and warlords.
* The focus on identity rather than ideology as a driver of conflict, often using ethnic, religious or nationalist rhetoric to mobilise support and justify violence.
* The increasing importance of crimes against humanity and attacks on civilians, rather than conventional fighting between armed forces.
* The growing involvement of international and transnational actors, both in terms of funding and support for the parties in conflict, and in terms of efforts to resolve conflicts or mitigate their humanitarian impact.

These 'new wars' present distinct challenges in terms of prevention, resolution and post-conflict reconstruction, and require different strategies and approaches from those that were effective in the 'old wars'.

In her analysis of the new wars, Mary Kaldor argues that the post-1989 era is marked by three key elements. The first is globalisation. The end of the twentieth century was characterised by an acceleration of globalisation, profoundly transforming economic, political and cultural relations at a global level. This globalisation has direct repercussions on the nature of conflicts. The transnational financing of armed groups, the dissemination of extremist ideologies through digital media, and the involvement of international forces in peacekeeping operations are all phenomena that have resulted from it. Secondly, the post-1989 era is marked by a major transformation of political structures. With the end of the Cold War, many communist and authoritarian regimes collapsed, giving rise to new democracies. At the same time, international intervention in the internal affairs of states increased, often justified by the need to protect human rights or prevent genocide. Finally, Kaldor highlights a fundamental change in the nature of violence. Conflicts have become more diffuse and decentralised, involving a multitude of non-state actors. Deliberate attacks on civilians, the exploitation of ethnic or religious identity for mobilisation purposes, and the use of terror tactics have become commonplace. Thus, according to Kaldor, these three elements interact to create a new type of war, profoundly different from the traditional interstate wars of the past. 

According to Mary Kaldor, the modern era has seen a shift from ideologies to identities as the main drivers of conflict. In this context, battles are no longer fought for political ideals, but for the affirmation and defence of particular, often ethnic, identities. This development marks a step towards exclusion, as it can lead to increased polarisation and division in society. Unlike an ideological debate where there can be compromise and consensus, the defence of identity can create an "us against them" dynamic, which can be extremely destructive.

Mary Kaldor highlights this crucial shift in the grounds for conflict. When struggles were centred on ideologies, such as international socialism, they were more inclusive. The aim was to convince and rally as many people as possible to a cause, a system of thought or a vision of the world. By contrast, when conflicts are based on identity, particularly ethnic identity, they tend to be more exclusive. Fighting over a specific ethnic identity delimits a particular group as 'us', which inevitably implies a 'them' that is distinct and different. This creates a dynamic of exclusion that can be deeply divisive and lead to inter-community violence. This is a profound change from the ideological conflicts of the past.

Furthermore, according to Kaldor, the war is no longer for the people, but against the people, meaning that we are increasingly faced with actors who do not represent the state and who do not even aspire to be the state. Previously, conflicts were generally fought by states or by actors who aspired to control the state. War was therefore fought "for the people", in the sense that the aim was to gain control of the government in order, theoretically, to serve the interests of the people. In today's context, she argues that war is often waged "against the people". This means that non-state actors such as terrorist groups, militias or gangs are increasingly involved in conflicts. These groups do not necessarily seek to control the state and may in fact engage in acts of violence directed primarily against civilian populations. As a result, the nature of war has evolved to become less a struggle for control of the state and more a source of violence against the people. 

It is increasingly a bandit war, where the aim is to extract countries' natural resources for the personal enrichment of certain groups. Mary Kaldor describes this transformation as a form of "bandit war". In this context, war is not fought to achieve traditional political objectives, such as control of the state or defence of an ideology, but rather for personal or group enrichment. This new form of conflict is often characterised by the extraction and exploitation of natural resources in conflict-ridden regions. These "bandit wars" can have disastrous consequences for local populations, not only because of the direct violence they involve, but also because of the economic and social destabilisation they engender. Often, resources that could be used for economic and social development are instead diverted to private interests or groups, which can exacerbate poverty and inequality.

The post-Cold War era has seen the emergence of a global war economy, with non-state actors such as criminal organisations, terrorist groups and private militias playing an increasingly important role. These groups often rely on transnational networks to finance their operations, through drug trafficking, the illegal arms trade, smuggling of goods and other forms of organised crime. This war economy has the effect of prolonging conflicts, by providing armed groups with a means of financing their activities without the need for state or popular support. At the same time, it contributes to regional instability, as the profits from these illegal activities are often used to finance other forms of violence and disorder. In addition, these transnational networks make it more difficult for state authorities and international organisations to control and resolve conflicts. They often operate outside traditional legal frameworks and can spread across several countries or regions, complicating efforts to combat them. Finally, the involvement of non-state actors in conflicts can also have destabilising effects on states, undermining their authority and ability to maintain order and security. This in turn can aggravate tensions and conflicts, creating a vicious circle of violence and instability. [[File:Death of Pablo Escobar.jpg|thumb|right|Members of Colonel Hugo Martínez's Search Bloc celebrate over Pablo Escobar's body on December 2, 1993. His death ended a fifteen-month search effort that cost hundreds of millions of dollars, and involved coordination between the U.S. Joint Special Operations Command, the Drug Enforcement Administration, Colombian Police, and the vigilante group Los Pepes.]]

Mary Kaldor's approach to war can be seen as depoliticising. She argues that contemporary conflicts are primarily motivated by ethnic, religious or identity factors rather than political ideologies. This marks a break with the wars of the past, which were often fought in the name of a political ideology, such as communism or fascism. From this perspective, war is no longer a continuation of politics by other means, as the military theorist Carl von Clausewitz put it, but rather an act of violence motivated by differences in identity. This suggests that traditional solutions, such as political negotiations or peace agreements, may not be sufficiently effective in resolving these conflicts. 

The traditional view of war, as described by Carl von Clausewitz, sees it as "the continuation of politics by other means". From this perspective, war is seen as a tool that states use to achieve specific political objectives. However, according to Mary Kaldor and similar scholars, this dynamic has changed. They argue that in contemporary conflicts, traditional political objectives are often overshadowed by other motivations, such as ethnic or religious identity, or the desire to gain access to economic resources. In these cases, war no longer serves politics, but rather seems to be motivated by economic or identity interests.

We are faced with states that have emerged from decolonisation, mainly in the southern regions, which have undergone difficult nation-building processes. These states have often not been given the necessary tools for a solid and lasting structure. As a result, they have become fragile and unstable, a situation that encourages the emergence of conflict and violence. When these states begin to disintegrate, they give way to a degree of chaos where ethnic groups can find themselves in conflict with one another. At the same time, bandits and other non-state actors take advantage of this instability to further their own interests. The absence of a strong and effective state authority helps to perpetuate this disorder and prevents the establishment of a lasting peace.

The perspective put forward by Mary Kaldor, which suggests that political conflict is disappearing in favour of a form of global disorder, has had a significant impact on our understanding of contemporary transformations in warfare. According to this vision, weak or failing states would be incapable of ensuring stability on their territory, which would open the door to a whole range of threats and dangers. In the absence of state structure and control, chaos can emerge, generating often ethnic conflicts, criminal activity and unrestricted access to natural resources by various non-state groups. It is in this context that we are seeing an increase in civil wars and internal conflicts, fuelled by transnational networks such as mafias. The absence of a strong, stable state leads to a complex conflict landscape, where traditional political conflicts give way to a multitude of more diffuse and decentralised threats. This approach has played a key role in shaping our understanding of modern conflicts and the challenges to global peace and security.

The disorder seen in the Middle East has given rise to many concerns, often related to the concept of the state and its role as a stabilising entity. When the state seems unable to maintain control and order, this can lead to a multitude of threats and risks. In the case of the Middle East, these threats are diverse. They range from social and economic instability within countries, to increasing sectarian and ethnic conflict, to the risk of international terrorism. These conflicts can also lead to humanitarian crises, massive population displacements and refugee problems on a global scale. The absence of effective state control can also allow non-state actors, such as terrorist groups, to gain influence and power. For example, the Islamic State (EI) was able to emerge and take control of vast territories in Iraq and Syria by taking advantage of the weakness of local states and the prevailing chaos. This clearly illustrates the complexity of the issues linked to the absence of state control and instability, and the challenges they pose for international security.

Our conception of the international system is strongly rooted in the concept of the state. The state is generally considered to be the principal actor in international politics, ensuring security, order and stability within its borders. When a state collapses or is unable to exercise its authority effectively, this can have destabilising consequences for both the country concerned and the international community. The collapse of a state can lead to a power vacuum, creating fertile ground for the emergence of non-state armed groups, internal conflicts and widespread violence. This can also lead to a humanitarian crisis, with refugees fleeing violence and poverty, which in turn can create tensions in neighbouring countries and beyond. A state's inability to control its territory can also pose a threat to international security. It can create a space where terrorism, organised crime and other illicit activities can flourish, with potentially serious consequences beyond the borders of the state concerned. For these reasons, the collapse of states is often seen as a major source of instability and insecurity in the international system. It is therefore crucial for the international community to work together to prevent state collapse and to help restore stability when it does occur.

In the history of international relations, there have been cases where foreign powers have supported authoritarian or dictatorial regimes in order to preserve regional stability, contain a competing ideology, gain access to resources or for strategic reasons. However, this practice poses significant ethical problems and may be in contradiction with the democratic principles and human rights that these foreign powers often claim to defend. In the context of international politics, support for an authoritarian regime can sometimes reflect a preference for a state that firmly controls its country, even if this is at the expense of human rights or democracy. This tendency often stems from a concern for regional stability and international security. The idea is that, although these regimes can be repressive and undemocratic, they can also provide a degree of stability and predictability. They can prevent the chaos or violence that might otherwise emerge in the absence of strong state control, and they can also act as a counterweight to other regional or international forces perceived as a threat.

The nation state remains a fundamental structure for organising and understanding our societies and the world in which we live. It is through the state that we generally define our national identity, it is the state that represents citizens on the international stage, and it is through states that we most often structure our international interactions and relations. The nation state is also a key tool for maintaining public order, guaranteeing citizens' rights and freedoms, providing essential public services and ensuring national security. It therefore represents a degree of stability and predictability in an otherwise complex and constantly changing world.

The notion of "postmodern warfare" refers to a fundamental evolution in the art of war, moving away from traditional paradigms linked to nation-states in conflict for political or territorial reasons. At the heart of postmodern warfare is a depoliticisation of conflict, where political motives or territorial control are replaced by a multitude of factors such as ethnic, religious, economic or environmental disputes. This new era of warfare is also characterised by deterritorialisation, where conflicts are no longer restricted to specific regions but can become transnational or global, as in the case of international terrorism or cyber-conflicts. One of the most disturbing aspects of post-modern warfare is the privatisation of violence, with non-state actors such as terrorist groups, private militias and criminal organisations playing an increasingly prominent role. At the same time, the impact of conflict on civilians has intensified, with devastating direct effects such as violence, and indirect effects such as population displacement, famine and disease. 

Although democracies are less likely to go to war with each other - a concept known as 'democratic peace' - they continue to be involved in military conflicts. These conflicts often involve non-democratic countries or are part of international peacekeeping missions or the fight against terrorism. Northern countries also tend to use means other than conventional warfare to achieve their foreign policy objectives. For example, they may use diplomacy, economic sanctions, development aid and other "soft power" tools to influence other nations. In addition, technology has changed the nature of warfare. Northern countries, in particular, tend to rely heavily on advanced technology in their conduct of war. The use of drones, cyber attacks, and other forms of unconventional warfare is increasingly common. Ultimately, although the nature and conduct of war may change, the use of military force unfortunately remains a feature of international politics. It is therefore crucial that we continue to seek ways to prevent conflict and promote global peace and security.

== Towards a Postmodern War ==

[[File:MQ-9 Reaper taxis.jpg|thumb|MQ-9 Reaper taxiing.]]

Patterns of warfare have changed significantly, especially in Western countries. The main features of this change have been greater use of technology, increased professionalisation of armies and a growing aversion to human losses, often referred to as an "allergy to risk". The concept of the "Western Way of War" emphasises the preference for advanced technology and air superiority in the conduct of war. Technology has become a key element in the conduct of war, with the development of ever more sophisticated weapons, the use of drones, and the growing importance of cyber warfare. In addition, the increased professionalisation of the armed forces has resulted in more advanced training and greater specialisation of military personnel. Professional armies are becoming increasingly common, and conscription or drafts are less and less frequent in Western countries. The "allergy to risk" has been exacerbated by the fact that Western societies find it increasingly difficult to accept the loss of life in war. This has led to a preference for air strikes and the use of drones, which allow military operations to be carried out without endangering the lives of soldiers.

At present, there is a clear decline in social acceptance of the loss of human life in wars fought abroad. People are less and less willing to support conflicts that result in the loss of life, particularly of their own citizens. This situation is partly fuelled by ubiquitous and instantaneous media coverage of conflicts, which makes the human costs of war more visible and real to the general population. At the same time, technological advances have made it possible to fight wars from a greater distance. The use of drones, precision missiles and other cutting-edge technologies means that attacks can be carried out from a distance, without any direct risk to troops on the ground. This form of technological warfare is largely the result of technological developments facilitated by governments.

The use of drones in modern conflicts has radically changed the nature of warfare. The piloting of drones makes it possible to conduct military operations, including lethal strikes, from thousands of kilometres away. The personnel who control these drones often do so from bases located outside the battlefield, sometimes even in another country. This raises a number of ethical and moral questions. On the one hand, it minimises the risk to the military forces controlling these drones. On the other hand, it can create a disconnect between the act of killing and the reality of war, which in turn can have psychological consequences for drone operators. In addition, it can make decision-making on the use of force less immediate and less personal, potentially lowering the threshold for the use of force. The use of drones also has strategic implications. It enables precise strikes to be carried out with minimal risk to military forces, but it can also lead to civilian casualties and collateral damage. The use of drones therefore raises important questions of international humanitarian law and responsibility.

The question is whether this distancing changes the nature of war, whether it represents an evolution, a revolution in military affairs with the concept of "zero death" war, whether we need to go beyond Clausewitz when we talk about Mary Kaldor, for example. Putting war at a distance thanks to technology, particularly drones, raises the question of whether the very nature of war is changing. The ability to conduct military operations without directly endangering the lives of one's own soldiers undeniably changes the experience of war and can influence decision-making on the use of force. The concept of "zero death war" may seem attractive from the point of view of those who wage war, but it should not obscure the fact that even a war waged from a distance can have devastating consequences for civilians and result in the loss of human life. Whether we should "go beyond Clausewitz" is a matter of debate among military theorists. Clausewitz argued that war is an extension of politics by other means. Although technology has changed the way war is fought, it can be argued that the ultimate objective remains the same: to achieve political goals. From this perspective, Clausewitz's thinking is still relevant. That said, the work of scholars such as Mary Kaldor has highlighted that contemporary forms of organised violence may differ from the traditional models of war envisaged by Clausewitz. The 'new wars', according to Kaldor, are characterised by intra-state violence, the involvement of non-state actors, and the growing importance of identities rather than ideologies. These transformations could lead us to rethink some of the classic theories of war.

Is war really changing? Is it something that is becoming increasingly depoliticised in the countries of the South, and is ultimately something eminently technological where there is no longer any connection with what is happening on the ground? The perception of war as something distant and technological, particularly in the West, may be a growing phenomenon. However, to claim that war is becoming 'depoliticised' requires a more nuanced analysis. 

In the countries of the South, although there is an increase in intra-state conflicts and violence perpetrated by non-state actors, these conflicts remain deeply political. They may be linked to struggles for control over resources, ethnic or religious differences, aspirations for self-determination, or reactions to corruption and poor governance. Moreover, organised violence can have major political implications, influencing power structures, altering relations between groups and shaping a country's political future. In Northern countries, the use of technologies such as drones can give the impression of a 'dehumanisation' of warfare, where acts of violence are committed from a distance and in a seemingly detached manner. However, this approach to war can have its own political implications. For example, the apparent ease with which violence can be inflicted remotely may influence decisions about when and how to use force. In addition, the way in which these technologies are used and regulated can give rise to important political debates. It is therefore crucial to understand that while the nature and conduct of war may evolve, war remains a profoundly political enterprise, and its consequences are felt far beyond the battlefield.

We're talking about all the wars we see on the screens, such as the Gulf War in the 1990s, which seem remote because we don't even experience them through our own families or our own experiences. The Gulf War in the 1990s marked a turning point in the way war is perceived by the public. The war was widely covered by the media, with images of the war broadcast live on television. This helped to create a certain distance between the public and the real conflict. By viewing the war through the television screen, it can seem distant and disconnected from our daily lives. This distance can also be accentuated by the fact that fewer and fewer people in Western countries have direct experience of military service. Whereas military service was once a common experience for many men (and some women), many countries now have fully professional armies. This means that war is experienced directly by a smaller percentage of the population. Although war may seem remote to many people in Western countries, it has very real consequences for those who are directly involved in it, be it the military deployed in conflict zones or the local populations affected. In addition, although a conflict may seem geographically remote, it can have indirect consequences through phenomena such as refugee flows, economic impacts or threats to international security.

= Annexes =
*Leander, Anna. Wars and the Un-Making of States: Taking Tilly Seriously in the Contemporary World
*Goldstone , Jack A.  States Making Wars Making States Making Wars...  in  Contemporary Sociology, Vol. 20, No. 2 (Mar., 1991), pp. 176-178. Url: https://www.jstor.org/stable/pdf/2072886.pdf?acceptTC=true
*Kaldor, Mary. New & Old Wars. Stanford, CA: Stanford UP, 2007. Print.
*[[La naissance de la guerre moderne : war-making et state-making dans une perspective occidentale]]
*Tilly, Charles. War Making and State Making as Organized Crime. url: http://www.homeworkmarket.com/sites/default/files/q3/28/02/reading_response_4_2.pdf
*NATO StratCom COE; Mark Laity. (2018, August 10). What is War?. Retrieved from https://www.youtube.com/watch?v=Gj-wsdGL4-M

= References =
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[[Category:Stephan Davidshofer]]
[[Category:science-politique]]
[[Category:relations internationales]]
[[Category:sécurité]]