We assess the degree to which propositions from Samuel Huntington's The Clash of Civilizations and the Remaking of World Order can account for the incidence of militarized interstate disputes between countries during the period 1950-92. We find that such traditional realist influences as contiguity, alliances, and relative power, and liberal influences of joint democracy and interdependence, provide a much better account of interstate conflict. Pairs of states split across civilizational boundaries are no more likely to become engaged in disputes than are other states ceteris paribus. Even disputes between the West and the rest of the world, or with Islam, were no more common than those between or within most other groups. Among Huntington's eight civilizations, interstate conflict was significantly less likely only within the West; dyads in other civilizations were as likely to fight as were states split across civilizations, when realist and liberal influences are held constant. The dominance of a civilization by a core state, democratic or not, does little to inhibit violence within the civilization. Contrary to the thesis that the clash of civilizations will replace Cold War rivalries as the greatest source of conflict, militarized interstate disputes across civilizational boundaries became less common, not more so, as the Cold War waned. Nor do civilizations appear to have an important indirect influence on interstate conflict through the realist or liberal variables. They help to predict alliance patterns but make little contribution to explaining political institutions or commercial interactions. We can be grateful that Huntington challenged us to consider the role that civilizations might play in international relations, but there is little evidence that they define the fault lines along which international conflict is apt to occur.
Russett, Bruce M.; John R. Oneal & Michaelene Cox (2000) Clash of Civilizations, or Realism and Liberalism Déjà Vu? Some Evidence, Journal of Peace Research 37 (5): 583–608.