This chapter develops a theory to explain why counterrevolutions emerge and succeed. This movement-centric theory emphasizes the strategies movement leaders embrace, which, more than anything else, define the capacities and interests of the old and new regimes during the post-revolutionary transition. All revolutionary governments enjoy an initial power advantage over the old regime. Whether a counterrevolution emerges depends on how much capacity these old regime forces have left and how much their interests are threatened by revolutionary rule. And whether their counterrevolutions succeed depends on how effectively revolutionaries can preserve their initial capacity through the tumultuous transition. Specifically, the chapter lays out a post-revolutionary “governance trilemma,” which requires new leaders to simultaneously manage the concerns of lingering old regime forces, elites in their coalition, and popular groups who supported the revolution. The chapter then explains how these dynamics differ following two ideal-typical forms of revolution: radical-violent movements and moderate-unarmed movements. Counterrevolutions are less likely to emerge following extreme versions of both movements – because the former lowers counterrevolutionary capacities and the latter lowers their interests in restoration. However, counterrevolutions are more likely to succeed against moderate-unarmed movements, because they establish governments that lack key tools for effectively navigating the governance trilemma.