This synthetic and interpretive history highlights the centrality of war to the modern Japanese experience. The volume examines how World War I set off profound changes that led to the rise of a politicized military, aggressive imperial expansion, and the militarization of Japanese social, political, and economic life. War was extraordinarily popular, which helped confirm Japan’s aggressive imperialism in the 1930s and war across the Asia-Pacific in the 1940s. It took a defeat by 1945 and occupation through 1952 to undo war as a national concern and to remake Japan into a peaceful nation-state.