Are 'Dear John' letters lethal weapons in the hands of men at war? Many US officers, servicemen, veterans, and civilians would say yes. Drawing on personal letters, oral histories, and psychiatric reports, as well as popular music and movies, Susan L. Carruthers shows how the armed forces and civilian society have attempted to weaponize romantic love in pursuit of martial ends, from World War II to today. Yet efforts to discipline feeling have frequently failed. And women have often borne the blame. This sweeping history of emotional life in wartime explores the interplay between letter-writing and storytelling, breakups and breakdowns, and between imploded intimacy and boosted camaraderie. Incorporating vivid personal experiences in lively and engaging prose – variously tragic, comic, and everything in between – this compelling study will change the way we think about wartime relationships.