There are number of theories on this subject that have subsumed and grown beyond liber-alism. They incorporate and synthesize factors and insights from other theoretical perspectives like realism. For example, Randall Schweller combined domestic political institutions with the international distribution of power (so he combined liberal and realist insights) in his analysis of power shifts and preventive war. His study of all preventive wars since 1665 found that declin-ing democracies do not launch preventive war against risdeclin-ing opponents. When the risdeclin-ing rival is a democracy, the declining democracy will accommodate to the rising state (for example, Great Britain’s accommodation of the rise of the United States in the late-1800s and early-1900s). When the rising rival is nondemocratic, the declining democracy will form a counterbalancing alliance.
He also found that declining nondemocracies are likely to launch preventive wars against both rising democracies and other nondemocracies.45
Lars-Erik Cederman proposes a reinterpretation of Kant’s democratic peace hypothesis by ar-guing that Kant’s logic on the development of perpetual peace among democratic republics “de-pends on the idea of progress through learning.” Thus, Cederman argues it is possible to explain the “near misses” in the 1800s when democracies almost went to war with each other, as well as the increasingly stable and peaceful relationships among democracies subsequently, through two learning processes. Democratic states undergo dynamic learning processes in which they alter their behavior by taking into account their experiences. As they mature over time, democracies become more peaceful and more cooperative with each other. They also undergo a dialectical learning process because there is not always positive progress. In other words, major reversals oc-cur in the form of world wars, and these events drive home the point that it is better to eliminate the use of force in interstate relations. He concludes that history supports his point: democratic state interactions have become more peaceful over time since 1837. Not only does war not occur among mature democracies, but also the use of military force has come to be considered illegiti-mate except in exceptional circumstances. Interestingly, Cederman found that norms of peaceful conflict resolution exist not only among democracies, but have spread to a limited extent among nondemocracies.46
Bruce Russett and John Oneal propose a different reinterpretation of Kant. Kant contended, in their view, that perpetual peace among states is possible, but it must be founded on three ele-ments: republican democracies, free trade and economic interdependence, and international orga-nizations. While these three elements are obviously linked—democracies engage in high levels of
trade, and economic exchanges have resulted in the creation of a large number of international or-ganizations to manage and regulate international economic intercourse and interstate relations—
they are not combined in a single theory explaining democratic peace. Instead, Russett and Oneal make a general argument that the elements interact to produce a “virtuous circle” resulting in peace. They test the individual elements by analyzing war, conflict, and militarized disputes over two centuries. They conclude that there is clearly “a separate peace among democratic states.”
Furthermore, the overall risk of war and conflict declined as the number of democracies increased.
They also found there is strong evidence that increasing economic interdependence among states reduces the incidence of conflict among them and that states “open to the global economy are more peaceful than average.” Finally, they found that a dense network of international organizations reduces the incidence of conflict.47
Mark Haas focuses on political ideology and how this influences the likelihood of conflict and war. He synthesizes concepts from liberalism, realism, social identity theory, and transnational-ism to build the argument that the greater the ideological gap between countries, the more likely war will occur. This is because different views on the proper ordering of domestic politics oper-ate through various social and communications mechanisms to produce a high threat perception.
For example, the political ideologies that underlay liberal democracy and communism are dia-metrically opposed—the gap between the ideologies is wide. For the United States and the Soviet Union, this produced a fear of subversion by the other side, an “us” versus “them” dynamic that encouraged mistrust and undermined the effectiveness of communications. Taken together, these processes produced mutual high-threat perceptions. Relative power capabilities were then fac-tored in by political leaders to produce specific foreign policies. In the case of the Cold War, each side viewed the other as a threat, fearing the rise of the other’s power, and therefore each side adopted hard-line policies such as nuclear armament. This process can reverse when the gap in political ideologies lessens. An example is the political reforms undertaken by Mikhail Gorbachev in 1988. As Gorbachev implemented democratic reforms, the threat perceptions changed signifi-cantly, as did foreign policies. This ultimately led to a peaceful end to the Cold War. Haas applied his argument to all great power conflict between 1789 and 1989, finding that the evidence supports his argument.48 Interestingly, this argument can be applied to nonstate actors, and it provides a compelling explanation for why the United States views al-Qaeda’s Islamic jihadism as so threat-ening. It also explains why al-Qaeda has repeatedly attacked the United States and a variety of other targets.
CONCLUSION
Democracy as a form of political organization fundamentally changed the relationship between the people/citizens and the state/political leaders. It meant that leaders were representative of and accountable to their voters. It also changed the nature of international relations. As democracy has spread around the world, the reasons states go to war and the states they go to war against have changed. The democratic peace research program has studied the patterns of cooperation and conflict among states based upon its wide variety of tools for scientific inquiry, reaching a number of important conclusions. Democratic peace theory does not claim that “democracies do not fight each other.” Rather, it takes the position that “democracies are highly unlikely to fight each other.”
It also observes that there is no instance in history in which liberal democracies have fought each other.49 Democracies are slow to go to war, but when they do, they are more likely to prevail.
Democracies join the same side in war, and they are more likely than other forms of government to ally with one another. Democracies are also more reliable alliance partners. Democracies are not necessarily less war prone than other types of states (they are not pacifist), but they are peace
prone in their relations with each other, and they tend to be war prone only with nondemocracies.
Democracies trade with each other, they form long-lasting international organizations, and they obey international law.50 Only liberal democracies have been able to form a separate peace among themselves; no other form of government has accomplished this. Throughout history, tribes, clans, feudal societies, monarchies, autocracies, and communist states have fought each other. The lib-eral democratic zone of peace has endured over time, despite periodic conflicts of interest, and it has expanded as more states have democratized.
Democratic peace theory poses a challenge to realism. It does not refute realism, but it narrows the scope of conditions under which realist assumptions and factors apply. For this reason, it has been repeatedly challenged. The critics of democratic peace theory have argued there is insuf-ficient empirical evidence to draw firm conclusions. John Mearsheimer avers that “democracies have been few in number over the past two centuries, and thus there have not been many cases where two democracies were in a position to fight each other.”51 This view was valid until the mid-20th century. However, since decolonization and the modern waves of democratization across Asia, Latin America, Europe, and the former Soviet Union in the 1970s, 1980s and 1990s, democra-cies are no longer few. In the 1800s, there were only a handful of developing democrademocra-cies; by 1900, there were 33 democracies; by the 1960s, there were 52;52 and by 2011, there were 115.53 To respond to the critics, democratic peace researchers strive to conduct scientifically rigorous analysis. They use multiple methodologies, such as case studies and statistical analysis, to maximize reliability and validity. They have analyzed all interstate conflict over the last 2 centuries (and in some cases beyond), and they have developed sophisticated explanations for how peace is achieved through the interaction of multiple variables such as ideas, ideology, democratic political institutions, eco-nomic interdependence, international organizations, perception, and learning. This research has led to the indisputable observation that the democratic peace exists. Some even assert that the absence of war among democracies is the closest thing international relations theory has to an empirical law.54
Liberal scholars and democratic peace analysts do not argue that war will disappear in inter-national relations. In fact, they argue war is sometimes necessary and that war can be just, such as war to protect self and territory, to protect friends, and to free the oppressed. Since war will never be eliminated, however, it must be codified and brought under some form of civilized con-tainment. Various scholars have worked to identify just and unjust war. This goal is very old, for it dates back to Saint Thomas More (early-16th century), Hugo Grotius (early-17th century), and Eméric Vattel (18th century).55
All such scholarly investigation has implications for U.S. policy. A state’s transition to democ-racy will not necessarily make the United States more secure, especially if the standard for labeling a nation a democracy is whether it formally goes through the motions of holding periodic elec-tions. Only liberal democracies will ensure security. Furthermore, the liberal democracies must be mature, and their political institutions and democratic values consolidated.56 However, democratic consolidation takes time, and regression to autocracy during the transition process from a non-democratic to a non-democratic regime is common.57 Fortunately, transitional states in the modern era are not alone, and the international community has mechanisms to assist them as they transition and democratize. The transition of the post-communist countries in Central and Eastern Europe is a prime example. The United States and Western Europe were able to capitalize on trade op-portunities and the desire of the transitioning states to join Euro-Atlantic international institutions.
The accession criteria for NATO and EU membership required substantial social, economic, and political reforms—in effect, they required the aspirant countries to become consolidated liberal democracies. In the end, the policies of the Clinton and both Bush administrations achieved their
goals for Europe—today the European continent is stable and secure, and most of the post-com-munist states are largely consolidated liberal democracies. Whether the Arab Awakening and the democratic transitions in Iraq and Afghanistan will also result in consolidated liberal democracies is an open question. Arguably, more extensive social and cultural changes need to take place in the Arab world than in the post-communist states. Without similar internal aspiration for democratic reform and external incentives linked to trade and membership in international organizations, the road to democratic consolidation will be longer and harder and is not a sure thing.