Ethnic Conflicts

Jerry Muller ("Us and Them," March/April 2008) tells a disconcerting story about the potential for ethnic diversity to generate violent conflict. He argues that ethnic nationalism -- which stems from a deeply felt need for each people to have its own state -- "will continue to shape the world in the twenty-first century." When state and ethnic-group boundaries do not coincide, "politics is apt to remain ugly."

Muller points to the peace and stability in Europe today as evidence of the triumph of "the ethnonationalist project": it is only because of a half century of violent separation of peoples through expulsions, the redrawing of state boundaries, and the outright destruction of communities too weak to claim territories of their own that Europe today enjoys relative peace. Elsewhere, the correspondence between states and nations is much less neat, and there Muller seems to agree with Winston Churchill that the "mixture of populations [will] ...cause endless trouble." He advocates partition as the best solution to this difficult problem.

If correct, his conclusion has profound implications both for the likelihood of peace in the world and for what might be done to promote it. But is it correct? Do ethnic divisions inevitably generate violence? And why does ethnic diversity sometimes give rise to conflict?

In fact, ethnic differences are not inevitably, or even commonly, linked to violence on a grand scale. The assumption that because conflicts are often ethnic, ethnicity must breed conflict is an example of a classical error sometimes called "the base-rate fallacy." In the area of ethnic conflict and violence, this fallacy is common. To assess the extent to which Muller falls prey to it, one needs some sense of the "base."

How frequently does ethnic conflict occur, and how often does it occur in the context of volatile mismatches between ethnic groups and states? A few years ago, the political scientists James Fearon and David Laitin did the math. They used...