The number, size, and scope of peacekeeping missions deployed in the aftermath of civil wars have increased exponentially. From Croatia and Cambodia, to Nicaragua and Namibia, international personnel have been sent to maintain peace around the world. But does peacekeeping work? And if so, how? Virginia Page Fortna answers these questions through the systematic analysis of civil wars that have taken place since end of the Cold War. She compares peacekeeping and non peacekeeping cases, and she investigates where peacekeepers go, showing their missions are crucial to most severe internal conflicts in countries and regions where peace is otherwise likely to falter. She shows that peacekeeping is an extremely effective policy tool, reducing risk that war will resume. Moreover, she explains that small and militarily weak consent-based peacekeeping operations are often just as effective as larger, more robust enforcement missions. She examines causal mechanisms of peacekeeping, paying particular attention to perspective of the peacekept, the belligerents themselves, on whose decisions the stability of peace depends. Based on interviews with government and rebel leaders in Sierra Leone, Mozambique, and the Chittagong Hill Tracts in Bangladesh, she demonstrates specific ways in which peacekeepers alter incentives, alleviate fear and mistrust, prevent accidental escalation to war, and shape political procedures to stabilize peace--Publisher's description.