Japan matters in the history classroom because its development as a modern country offers rich opportunities for comparison. Japan’s rapid change from a system with some characteristics of feudalism in the Tokugawa period to modernization in the Meiji period is unlike any other shift in world history. The economic, social, and political changes were so rapid that they destabilized the fabric of the nation and put them on the path toward conflict with the Western nations as well as with their Asian neighbors. Japan’s need to be a modern nation and an equal to Western powers gives students a case study on modernity and all its trappings. Empire building was on its way out following World War I, and Japan’s perceived need to create an empire in Asia ended in a war that devastated them. The Occupation of Japan (1945–52) provides yet another case study for students. US idealism to recreate Japan as a democratic, peaceful nation encourages American students to understand their own nation while examining the Occupation. Japan’s social and economic success in the postwar period stands as a model in the minds of policy makers of how military occupations can be successful. The occupations of Iraq and Afghanistan in our present time are guided—and misguided—by the postwar occupations of Japan and Germany. The world we live in today is connected to the postwar period just as it is connected to all history. Japan matters because its modern history is one example of what happens in nations that develop too rapidly and as a result are more likely to experience internal and external conflict. Cooperation and economic interdependence among nations supersedes military aggression and empire building. Democracy and governments that provide for the general welfare of their citizens are the favored models. Therefore, the construct of the world today can be found in and attributed to Japan’s modern historical development.