Do democratic states have a distinctive approach to international conflicts? Perhaps the most significant discovery-indeed rediscovery-in the recent study of international relations is the "democratic peace" hypothesis. Democracies never (or very rarely) go to war against other democracies. Debates about definitions aside, this is a powerful finding. As Jack Levy has noted, "the absence of war between democracies comes as close as anything we have to an empirical law in international relations.25
Competencies: The Rediscovery of the Democratic Peace The democratic peace has been "rediscovered" because two centuries ago the German philosopher Immanuel Kant in his essay "Perpetual Peace" outlined the conditions of international and domestic politics that he believed would lead to the "ever-widening pacification" of international life.26 Kant's analysis is subtle and complex, but, simply stated, his conditions for peace are three. The first and most important relates to the domestic political regimes of states: peaceful nations must be "republics," by which Kant meant states in which citizens have rights and governments that depend on the consent of the governed. In republics, the public would oppose wars because they would not want to bear the cost of fighting. As Kant argued:
If the consent of the citizens is required to decide that war should be declared, nothing is more natural than that they would be very cautious in commencing such a poor game, decreeing for themselves all of the calamities of war. Among the latter would be: having to fight, having to pay the costs of the war from their own resources, having painfully to repair the devastation war leaves behind, and, to fill up the measure of evils, load themselves with a heavy national debt that would embitter peace itself.. . .
Kant's second condition focuses on economics: republics should have market economies aimed at improving citizens' well-being. Then, given an international division of labor through free trade, economic interdependence will evolve. Benefiting from these arrangements, citizens will be more reluctant to break the ties of trade. In Kant's view, through commerce "a peaceful traffic among nations was established, and thus understanding, conventions, and peaceable relations were established among the most distant peoples." Although skeptics point to examples like World War I, which broke out despite unprecedented high levels of international commerce, recent scholarly studies find evidence to support Kant's view.27
Third, Kant argued that international peace required the emergence of a "pacific union" among republics. This would occur because republics would respect other republics and rely on principles of peaceful dispute resolution, leading to peace among themselves. Kant foresaw a lengthy process in which the pacific union would expand gradually as other states noted the benefits democracies enjoyed and sought to emulate them. By gradual extension, peace would become global and finally perpetual.
When Kant wrote in 1795, there were only a handful of republics that met his conditions. But the central tenets of his analysis appear more profound and more powerful in the light of the past two hundred years. Modern scholars focus on democracies-states in which leaders are selected in free and fair elections-instead of what Kant called republics. They debate definitions and borderline cases such as the Spanish-American War of 1898. Nonetheless, most scholars who have examined the evidence conclude that the absence of war between democracies is statistically significant, not the result of random chance or factors other than shared democracy.28
Recent debate about the democratic peace hypothesis has added caveats and qualifications to the basic proposition. First, most findings suggest that democracies enjoy peace only with one another. They are as likely to fight nondemocracies as any other state would be. Second, states making a transition to democracy have often been more likely to engage in war.29The upsurge in mass political involvement in pluralizing, democratizing states encourages leaders to mobilize support around calls for aggressive international and colonial activity. From the mid-nineteenth to early twentieth century, Britain, Napoleon III's France, and Wilhelmine Germany exemplified this pattern. States that were colonized or victimized (for example, China in the Opium Wars) are acutely aware of this phenomenon. Finally, it is critical to distinguish between democracy and liberalism in explaining peace among nations. John Owen and Fareed Zakaria have argued that it is liberal beliefs and institutions, not the democratic electoral process, that are mostly responsible for the "democratic" peace.30
Our review of the historical record, and the challenges ahead, leads us to several not-altogether-comfortable conclusions about the special responsibilities of democracies to prevent deadly conflict in the decade or two ahead.
First, the major democracies are likely to be the most important actors in preventing deadly conflict for three inescapable reasons: (1) resources (power, troops, money); (2) values; and (3) knowledge. In the international system today, and for the foreseeable future, states that command the most resources-power, military force, economic advantages-have the greatest capacity to take action-for good or ill. This fact remains unpleasant for smaller, weaker states, who are thus more inclined to advocate universal international action alone. The states most likely to care about justice-including freedom, human rights, and the rule of law-in acting to prevent deadly conflict are states that cherish such values in their own political systems. In the current political system, these states are also likely to have the greatest amount of information and knowledge about conditions in which deadly conflict is likely and actions that are likely to be effective in preventing deadly conflict.
Second, the states most likely to act to prevent deadly conflict-but without attention to justice-are states that have traditional geopolitical interests: borders, citizens or ethnic affiliates in the country in question, established economic interests in the country where conflict is occurring, colonial or imperial relationships, or geopolitical aspirations. Such states are likely to produce the principal initiatives resulting in conflict prevention-but not in promoting justice at the same time. Examples abound: Vietnam in Cambodia, India in Bangladesh in 1971, Russia in its "near abroad."
Third, "coalitions of the willing," for example, IFOR in Bosnia, offer one of the most promising approaches, for such coalitions suggest a convergence of interests and values that makes action to prevent deadly conflict in ways that respect justice more likely. Moreover, since multilateralism limits the scope for specific national interests that infringe justice, coalitions increase the likelihood that "justice" considerations will be incorporated in the actions preventing deadly conflict. Coalitions' efforts operating under UN mandates are still more likely to balance the narrower interests of the states most willing to act with the broader interests of justice.
Important researchable questions include: