The 1949 Geneva Conventions are the most important rules for armed conflict ever formulated. They continue to shape contemporary debates about regulating warfare. But their history is often misunderstood. For many observers, the drafters behind these treaties were primarily motivated by liberal humanitarian principles and the shock of the atrocities of the Second World War. This book tells a different story. It shows how the final text of the Conventions, far from being an unabashedly liberal blueprint, was the outcome of a series of political struggles among the drafters. It also concerned a great deal more than simply recognizing the shortcomings of international law as revealed by the experience of war. This book, based upon meticulous archival research and critical legal methodologies, argues that a better way to understand the politics and ideas of the Conventions’ drafters is to see them less as passive characters responding to past events than as active protagonists trying to shape the future of warfare. In many different ways, they tried to define the contours of future battlefields by deciding who deserved protection and what counted as a legitimate target. Outlawing illegal conduct in wartime did as much to outline the silhouette of humanized war as to establish the legality of waging war itself. Although they did not seek war as such, drafters prepared for it by means of weaving a new legal safety net in the event that their worst fear should materialize—a specter still haunting us today.