Once a civil war ends, there is high probability that the nation will relapse into renewed war within a few years. For a nation where a civil war has recently ended to relapse into renewed conflict, some dynamic process of contention must emerge that makes a resumption of armed conflict one—but not the only—possible outcome of that contentious episode. We can conceive of the dynamics by which contentious politics can lead to civil war recurrence as a function of three conditions. First, one or more dissident groups must emerge with the organizational and military capacity to mount and sustain an armed challenge to the postwar state. Second, one or more of those groups must have the incentive to resort to armed conflict rather than abide by the post–civil war order. Third, conditions and events in the postwar environment must evolve in a manner such that one or more of these groups must determine that they have an opportunity to revolt. This framework can be used to analyze how, in existing research, the outcome and key attributes of the now-ended civil war and conditions in the postwar environment affect whether dissident groups will resume armed conflict or sustain the peace.