This volume provides fresh perspectives on the international strategic environment between the two world wars. At London in 1930, the United States, Great Britain, and Japan concluded an important arms control agreement to manage the international competition in naval armaments. In particular, the major naval powers reached agreement about how many heavy cruisers they could possess. Hailed at the time as a signal achievement in international cooperation, the success at London proved short-lived. France and Italy refused to participate in the treaty. Even worse followed, as within a few years growing antagonisms among the great powers manifested itself in the complete breakdown of the interwar arms control regime negotiated at London. The resulting naval arms race would set Japan and the United States on a collision course toward Pearl Harbor. In addressing this important question, the authors uncover new evidence about the role of intelligence and behind-the-scenes political deal making that adds much to our knowledge of the international and naval history of this important era. This volume’s authors provide the first complete account of the strategic calculations and negotiations that shaped the outcome at the London Conference. No one interested in twentieth-century naval history, international relations and the rivalries of rising and declining great powers, and the origins of the Second World War can afford to miss this important new history.