Book excerpt: This book explores the rise and impact of violent non-state actors in contemporary Africa and the implications for the sovereignty and security of African states. Each chapter tackles a unique angle on violent organizations on the continent with the view of highlighting the conditions that lead to the rise and radicalization of these groups. The chapters further examine the ways in which governments have responded to the challenge and the national, regional and international strategies that they have adopted as a result. Chapter contributors to this volume examine the emergence of Islamist terrorists in Nigeria, Mali and Libya; rebels in DR Congo, Central African Republic, Ethiopia and Rwanda; and warlords and pirates in Somalia, Uganda and Sierra Leone.