The African continent is plagued by some of the most brutal and violent conflicts in the world. At the same time that warfare is changing, so has the state’s capacity to provide security and political stability to its citizens. This book deals with the role of regional organizations in Africa’s security. It focuses on three basic—yet often overlooked—questions: (1) the advantages and disadvantages of African regional and sub-regional organizations vis-à-vis other security mechanisms, (2) the official and unofficial reasons to intervene, and (3) whether security is actually protected by the peace activities carried out by the regional organizations. The contributors to the book—all leading researchers in the field—systematically assess and compare the role of the African Union (AU), the Economic Community of West African States (ECOWAS), the Intergovernmental Authority on Development (IGAD), the Economic Community of Central African States (ECCAS), and the Southern African Development Community (SADC). This book was based on a special issue of African Security.