War is a uniquely human scourge with complex biological, psychological, social, and political determinants. In this paper, repetition-compulsions both in making war and in the diagnosis and treatment of war trauma are documented. The diagnosis and treatment of war trauma are reviewed from the Napoleonic wars until the present, and parallel tracks in the development of military history, neurology, and psychoanalysis are traced. A personal history of the author and a clinical case history are included to demonstrate the effect of war on both family members and soldiers. Prevention of war through political negotiation is emphasized.