Why do nations decide to go to war? Based on an extensive study of inter-state wars since 1648, Richard Ned Lebow outlines his analysis of the motivations that underpin warfare. He finds that contrary to the expectations of most international relations theories, wars fought primarily for reasons of security, or material interests, have been relatively rare. Rather, motivations related to a nation’s ‘spirit’, such as the standing of a country or revenge, have been the primary causes of most wars.
There is a burgeoning literature on war and its causes. Almost all major studies approach the problem from a realist perspective. They assume security is the principal motive of states and insecurity the major cause of war. Realist theories elaborate mechanisms (balance of power) and conditions (security dilemma, polarity, power transition) that they consider responsible for conflict and war.
My dissatisfaction with the existing literature on war, and international relations more generally, was an incentive to write A Cultural Theory of International Relations (Cambridge University Press, 2008). That book develops a theory of international relations based on a parsimonious model of human motivation. Following Plato and Aristotle, I posit spirit, appetite and reason as fundamental drives with distinct goals. They generate different logics concerning cooperation, conflict and risk-taking. They require, and help generate, characteristic forms of hierarchy based on different principles of justice. A fourth motive—fear—enters the picture when reason is unable to constrain appetite or spirit. Fear is a powerful emotion, not an innate drive. In real worlds, multiple motives mix rather than blend, giving rise to a range of behaviours that often appear contradictory.
In modern times the spirit (thumos) has largely been ignored by philosophy and social science. I contend it is omnipresent. It gives rise to the universal drive for self-esteem, which finds expression in the quest for honor or standing. By excelling at activities valued by our peer group or society, we win the approbation of those who matter and feel good about ourselves.
Institutions and states have neither psyches nor emotions. The people who run these collectivities or identify with them do. They often project their psychological needs on to their political units, and feel better about themselves when those units win victories or perform well. Transference and esteem by vicarious association are especially pronounced in the age of nationalism where the state has become the relevant unit.
I documented the relevance of the spirit for war in a series of case studies in A Cultural Theory of International Relations. In Why Nations Fight (Cambridge University Press, 2010) I extend my analysis to war throughout the modern era and analyse war initiation in terms of the relative power of states and their respective motives for war. I constructed a data set of all inter-state wars involving great and aspiring rising powers from 1648 to the present. The data set identifies initiators of war (often multiple); their motives (security, material advantage, standing, revenge, and domestic politics); the outcome (win, lose, or draw); the nature of the rules, if any, governing warfare; the duration and intensity of the war; and the character of the peace settlement.
Contrary to realist expectations, I find security responsible for only 19 of 94 wars. A significant number of these wars pitted great powers against other great powers and none of them were associated with power transitions. This does not mean that security is unimportant in international affairs; it was a primary concern of all states that were attacked. Material interests are also a weak motive for war, being responsible for only 8 wars, and most of those in the eighteenth century. Security and material interest sometimes act in concert with one another, and more often with other motives. In some wars they are secondary to these other motives.
Standing, by contrast, is responsible for 62 wars as a primary or secondary motive. Revenge, also a manifestation of the spirit, is implicated in another 11. There can be little doubt that the spirit is the principal cause of war across the centuries, and that it and its consequences have been almost totally ignored in the international relations literature.
The character and robustness of domestic, regional and international societies and ideas about the efficacy of war determine the relative importance of various motives for war and its overall frequency. Interest shows a sharp decline once mercantilism gave way to more sophisticated understandings of wealth. Security-motivated wars show no similar decline by century but come in clusters associated with bids for hegemony by great or dominant powers.
The most recent clusters of security-related wars were associated with the run up and conduct of the two world wars of the twentieth century. They were in turn a product of the dislocations brought about of modernisation in an environment where great power competition and the drive for hegemony were conducted primarily by violent means. Now that this era has passed in Europe and is receding in much of the Pacific Rim, and hegemony achieved by force is no longer considered a legitimate ambition, the security requirements and fears of great powers should decline.
Wars of standing can also be expected to decline. During the post-war era, and even more since the end of that conflict, war and standing have become increasingly disengaged in the sense that successful war initiation no longer enhances standing. Successful war initiation may actually lead to loss of standing in the absence of United Nations’ approval of the military initiative in question. The Anglo-American intervention in Iraq—a war in which territorial conquest was not an issue—is a case in point. Changing values and norms encourage rational leaders to find other, peaceful ways of claiming standing. To the extent that this happens, the frequency of war involving either rising or great powers can be expected to diminish sharply.
I contend that three shifts in thinking have dramatically affected the frequency of war and its associated motives. The first concerns the nature of wealth. Until Adam Smith and modern economics, the world’s wealth was thought to be finite, with an increase in wealth for any state thought to result in a loss for others. When political elites learned that wealth could be augmented by the division of labour, mechanical sources of energy and economies of scale, and economic cooperation, war increasingly came to be seen as detrimental to wealth. This recognition all but put an end to wars of material aggrandisement.
The second shift concerns collective versus unilateral pursuit of security. Alliances assumed new meaning at the Congress of Vienna as they had the goal of conflict prevention. Later congresses helped great powers ease regional tensions through agreements and moral persuasion. Following World War I, the League of Nations was given the more ambitious task of preventing war by means of collective security, but failed miserably. The principle of collective security endured and the United Nations, established in 1945, made it the principal mission of the Security Council. The UN’s record is mixed, but the North Atlantic Treaty Organization (NATO) has been more successful. It and other international groupings have played a prominent and arguably successful role in keeping the peace or terminating wars in the post-Cold War world. Collective security has become the norm and an important source of regional and international stability.
The third and most recent shift in thinking concerns the nature of standing in international affairs. Historically, military success was the principal means of gaining standing and recognition as a great power. There are now other ways of achieving status. The European Union, Scandinavia, Canada, Japan and Brazil all claim standing on grounds that have nothing to do with military might. They emphasise their wealth, how they use it to help their citizens and less well-off countries and the public goods they provide for their regions or the international community.
The more robust regional and international orders become, the more multiple hierarchies of standing will also emerge at the international level. States will feel more confident about seeking standing in diverse ways and devoting resources toward this end that might otherwise be reserved for the military. If peace continues among the major powers, claims for standing on the basis of military power will become even less persuasive. As standing confers influence, states will have additional incentives to shift their foreign policies to bring them in line with the dominant incentive structure. In such a world states would view even more negatively the use of force in the absence of unqualified international support.
From the vantage point of say the year 2030, we might look back on the Iraq war as one of the defining moments of the international relations of the twenty-first century because of the way it delegitimised the unilateral use of force and foregrounded and encouraged alternative, peaceful means of gaining standing.
This article draws on material from Why Nations Fight: Past and Future Motives for War (Cambridge University Press, 2010)