Since the end of World War II, there have been four times as many civil wars as interstate wars. For a small subset of nations civil war is a chronic condition: about half of the civil war nations have had at least two and as many as six conflicts. This book presents an analytical framework that has been used to identify a set of factors that make civil war more or less likely to recur in a nation where a civil war has recently terminated. The outcome of the previous civil war -- whether it ended in a government victory, a rebel victory or a negotiated settlement -- as well as the duration and deadliness of the conflict affect the durability of the peace after civil war. The introduction of peacekeeping forces, investment in economic development and reconstruction, and the establishment of democratic political institutions tailored to the configuration of ethnic and religious cleavages in the society also affect the durability of peace after civil war. The book closes by applying these propositions in an analysis of the civil war in Iraq: what can be done to bring the Iraq conflict to an earlier, less destructive, and more stable conclusion?