Causes and Resolutions of Inter-State Conflicts

Wars between countries are among the oldest and most destructive features of international politics. When two or more sovereign states clash over land, power, or vital resources, the consequences can ripple across entire regions and the wider world. Understanding why these conflicts erupt, and how they can be brought to an end, is central to the study of peace and conflict. This post explores the main causes of inter-state conflict, the theories that explain why states go to war, and the methods countries use to resolve their differences before and after fighting begins.

What is an inter-state conflict? 🔗

An inter-state conflict is a dispute between two or more sovereign states that escalates into hostility, sometimes culminating in war. These conflicts typically involve military confrontations, diplomatic struggles, and in some cases full-scale war. What distinguishes them from internal conflicts such as civil wars is that the parties involved are independent states rather than groups within a single country.

Although the frequency of inter-state wars has declined since the end of the Second World War, partly due to the influence of international organisations like the United Nations, the threat has not disappeared. Tensions over borders, water, and political rivalry continue to shape relations between neighbouring states, including in South Asia.

The main causes of inter-state conflict 🔗

Inter-state conflicts rarely have a single cause. Instead, several factors usually overlap and reinforce one another. The most common drivers fall into three broad categories: political disputes, territorial claims, and competition over resources.

Territorial disputes 🔗

Disagreements over land are one of the oldest and most dangerous sources of conflict between states. A territorial dispute arises when two or more political entities lack consensus on borders and sovereignty over land, water, or airspace. Such disputes often stem from vague colonial-era boundaries, contested historical claims, or the strategic and cultural importance of a region.

Research in political science suggests that territorial disputes are among the most conflict-prone and the most likely to escalate into inter-state wars, and they are also among the most difficult to resolve. The long-running dispute between India and Pakistan over Kashmir is a clear example of how a territorial disagreement can shape relations between two states for decades.

Resource competition 🔗

Access to natural resources such as water, oil, minerals, and fertile farmland is essential to a state’s economy and security. When two states depend on the same resource, the potential for conflict rises. Territorial disputes are often related to the possession of natural resources such as rivers, fertile farmland, or mineral and petroleum reserves, which shows how closely the two causes are linked.

Water is a particularly sensitive resource in South Asia, where rivers cross national boundaries and serve hundreds of millions of people. The Indus river system, which flows through both India and Pakistan, has been the subject of careful diplomatic management precisely because the stakes are so high for agriculture and daily life in both countries.

Political and ideological differences 🔗

States with different political systems, governance structures, or ideological outlooks may find themselves at odds. Differing political systems and ideological leanings can place states at odds over how international affairs should be ordered. Security concerns add another layer: when one state strengthens its military, neighbouring states may feel threatened and respond by building up their own forces, creating a spiral of mistrust often described as a security dilemma. Alliances and historical grievances can further deepen these tensions and make conflict more likely.

Theories explaining inter-state conflict 🔗

Scholars have long tried to explain why states resort to war. Two thinkers offer especially influential frameworks: Carl von Clausewitz, who connected war to politics, and Kenneth Waltz, who identified different levels at which the causes of war can be located.

Clausewitz: war as a continuation of politics 🔗

Carl von Clausewitz was a nineteenth-century Prussian military theorist whose unfinished work On War remains a cornerstone of strategic studies. His most famous idea is that war is not merely a political act but a real political instrument, a continuation of political activity carried out by other means.

The point Clausewitz was making is that war is never an end in itself. It is a tool that states use to achieve political objectives when other methods have failed. Military force, in this view, must always remain subordinate to political purpose. This insight remains relevant today: modern analysts still apply his framework to contemporary battlefields, observing that tactical victories do not automatically translate into strategic or political success. A state may win battles yet fail to achieve its larger political goals, which is why Clausewitz insisted that policy must guide the conduct of war from start to finish.

It is worth noting that Clausewitz used the German word Politik, which scholars argue meant something broader than narrow policy. For him, politics included domestic power struggles as well as external policy objectives, giving his theory a wider reach than the famous one-line summary suggests.

Waltz: three images of the causes of war 🔗

Kenneth Waltz, a leading twentieth-century scholar of international relations, took a different approach in his 1959 book Man, the State, and War. Rather than offering a single explanation, he organised existing theories into three categories he called “images,” which are today commonly referred to as levels of analysis.

The first image: human nature. The first image locates the cause of war in individuals, whether in the flaws of particular leaders or in human nature more generally. Waltz summarised this view by suggesting that the wickedness or improper behaviour of human beings leads to war, while universal individual goodness would mean peace. The decisions of ambitious or aggressive leaders are often cited as examples of this image at work.

The second image: the internal structure of states. The second image looks inside the state itself, arguing that the way a country is organised politically and economically shapes its tendency towards war or peace. Some theories in this category claim that certain kinds of states, whether defined by their economic system or their form of government, are more prone to aggression than others.

The third image: international anarchy. The third image points to the structure of the international system. Because there is no overarching authority above sovereign states, the system is characterised by anarchy, and this anarchic structure is identified as the root cause of conflict. In a world without a central government to enforce order, states must ultimately rely on themselves for security, which can lead to suspicion, arms races, and war.

Waltz regarded the third image as the most important for understanding why wars recur, while accepting that the first two images remain necessary for a complete understanding of the causes of war. Together, the three images give students a powerful tool for analysing any conflict: we can ask whether its roots lie with individuals, with the states involved, or with the structure of the system as a whole.

Resolving inter-state conflicts 🔗

If war is the breakdown of politics, then conflict resolution is the effort to keep political and legal channels open. Diplomacy is the primary method by which states manage and settle their disputes, and international law provides a structured menu of peaceful options.

Diplomacy and the role of the United Nations 🔗

The Charter of the United Nations devotes an entire chapter to the peaceful settlement of disputes. Under Article 33, parties to any dispute that threatens international peace are obliged to first seek a solution through negotiation, enquiry, mediation, conciliation, arbitration, judicial settlement, or other peaceful means of their own choice. This is not merely a moral suggestion; the use of the word “shall” means it functions as a legal obligation for states to attempt peaceful settlement before escalating a dispute.

The Security Council can also call on states to use these methods, and the Secretary-General can offer “good offices” to help opposing sides communicate. In 2025, the Council reaffirmed this framework when it adopted Resolution 2788, urging member states to make effective use of the mechanisms set out in Article 33.

Negotiation, mediation, arbitration, and adjudication 🔗

Each peaceful method works differently. Negotiation involves the states themselves talking directly. Mediation and conciliation bring in a neutral third party, with conciliation involving more formal proposals. In arbitration, states submit their dispute to a neutral tribunal whose decision is binding and which functions somewhat like a private court. Judicial settlement, usually through the International Court of Justice, produces a binding legal ruling. These methods form a ladder of options that states can climb depending on how serious and intractable a dispute becomes.

A South Asian example: the Indus Waters Treaty 🔗

The Indus Waters Treaty of 1960, brokered by the World Bank, is often cited as a model of how a structured agreement can manage a sensitive resource dispute. It allocated the eastern rivers to India and the western rivers to Pakistan and established a three-tier dispute resolution mechanism that moves from technical discussion in the Permanent Indus Commission to a neutral expert and finally to a court of arbitration. For decades, this framework served as a core conflict-resolution tool that survived wars and political upheavals.

More recent developments show both the strength and the fragility of such mechanisms. India announced in April 2025 that it would hold the treaty in abeyance following a terror attack in Kashmir, which was followed by a brief but intense military confrontation that ended through an externally negotiated ceasefire. This episode illustrates a key lesson: institutional frameworks can absorb a great deal of strain, but they ultimately depend on the political will of states to keep using them.

When diplomacy fails 🔗

Diplomacy is the preferred path, but it does not always succeed. When negotiations collapse and peaceful mechanisms are abandoned, the risk of war rises sharply. This is exactly the point Clausewitz captured: war becomes the continuation of politics when other instruments have run out. International peace, even during the long absence of major war noted earlier, has often depended less on the inadequacy of peaceful mechanisms and more on whether states are genuinely willing to use them. As one analysis of the UN framework observed, failures in dispute settlement have largely been caused by an absence of political will on the part of states rather than by any shortcoming in the available measures.

Understanding both the causes of inter-state conflict and the tools for resolving it helps explain why some disputes simmer for decades while others are settled, and why the choice between war and peace so often comes down to political decisions made by states and their leaders.

What do you think? If most peaceful mechanisms already exist on paper, why do so many inter-state disputes still slide into conflict? And among Waltz’s three images, which do you find most convincing in explaining the wars you know about?

References

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13. https://copyright-certificate.byu.edu/news/article-33-of-the-un-1763329884799
14. https://vajiramandravi.com/upsc-exam/indus-water-treaty/
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16. https://www.securitycouncilreport.org/atf/cf/%7B65BFCF9B-6D27-4E9C-8CD3-CF6E4FF96FF9%7D/s_pv_4753.pdf