Why did Japan suddenly lurch from being a good international citizen in the 1920s to becoming a regional rogue in the 1930s? Usually Japan's Asian rampage is explained in terms of a deteriorating international context, increasingly violent and effective anti-Japanese Chinese nationalism, the dislocation of the Great Depression, and flaws in the Meiji constitution that facilitated the military's rise to power.
In addition, Japanese moderates had very little to show for their efforts to advance national interests diplomatically and through trade and investment, and they lost all legitimacy when the Western powers abandoned international cooperation in the wake of the depression. Their beggar-thy-neighbor protectionist policies hit Japan hard and gave ammunition to those who condemned the "weak-kneed internationalism" associated with Foreign Minister Kijuro Shidehara.
In this fascinating study of the Ministry of Foreign Affairs, or Gaimusho, Barbara Brooks examines the reasons for the demise of internationalism and the increasing sway of militarists over Japanese foreign policy. She challenges the orthodox position of Akira Iriye and other scholars that the 1930s was an aberration in Japan's modernization trajectory, arguing that institutional instability was characteristic of Japanese government since the Meiji era. She argues convincingly that institutional developments and a series of setbacks for the ministry explain a great deal about how the military came to dominate Japan's foreign policy.