The underlying rationale for the international humanitarian law of war is the protection of individuals and victims of war. This book is a contribution to the study of human rights in general and humanitarian law in particular. It contains detailed information and analysis of the law and practice relating to international armed conflicts involving irregular combatants. The discussion focuses on the most controversial provisions of Additional Protocol I to the Geneva Conventions: the classification of wars of national liberation, the treatment of guerrillas and mercenaries upon capture, reprisals, and the question of supervision and implementation in such conflicts. The manuscript on which this book was based was awarded the 1991 Paul Reuter Prize by the International Committee of the Red Cross.