The end of US-Soviet rivalry has given civil war a more prominent place in international politics, as well as in scholarship. The commonly held view that the world is currently in an era of more and increasingly savage civil conflict is, in part, a matter of increased attention to a problem that has long been with us. This article reviews recent research on the incidence of internal conflict. It finds that this literature calls into question assumptions of simple causal relationships between democratization, natural resources, ethnicity, and/or inequality and civil war. The most important area of consensus is that civil war, typical of weak states, is a problem of underdevelopment as well as politics.