Until the end of the Cold War, conventional wisdom held that civil wars necessarily ended in military victories. Nonetheless, over twenty negotiated settlements of civil wars have been reached since 1989 in places as disparate as El Salvador and South Africa. Some of these compromise settlements have ended civil wars and resulted in postwar regimes that are substantially more democratic than their predecessors. These settlements have often involved power sharing among the former contestants and other sectors of society. Many of these agreements have, as a central component, provisions to merge competing armed groups into a single national army. But how can people who have been killing one another with considerable skill and enthusiasm be merged into a single military force? Other than a few scattered case studies and some contradictory aggregate data analyses, we have very little information about the process of military integration. Why has it been used? What strategies have been most effective? Does integration help prevent renewed civil war? Recent research has produced a number of case studies which suggest some tentative answers to these questions. These are postwar cases, as opposed to cases of ongoing conflict. Military integration during the war is a much more difficult undertaking, as we have discovered in Afghanistan, although in both Uganda and Rwanda some integration was done during wartime, which served as a model for successful postwar policies. Many (although not all) examples of military integration are linked to negotiated settlements of civil wars. Such settlements, in turn, have become more common because military victories are increasingly difficult to achieve for several reasons. The issues in dispute now tend to involve identity rather than ideology, making it more difficult for the vanquished to “convert” to the victor’s position. Genocide and ethnic cleansing have become increasingly difficult to implement, making military stalemate increasingly likely. The end of the Cold War reduced external support for many Third World states, making them less able to count on big power support to win quick victories. The peace industry, the new complex of international and nongovernmental organizations dedicated to encouraging the end of mass violence, has also contributed.