The 7 December 1941 attack on the United States at Pearl Harbor by Japan was a gamble. Japan was already entangled in a long-standing, probably unwinnable war in China, which since its outbreak in mid-1937 had cost 185,000 Japanese dead and billions of yen. Pearl Harbor opened a second military front and dangerously committed Japan, with a relatively small population and limited economic capacity, to a full-scale Pacific War. For Southeast Asia, the war brought three and a half years of Japanese occupation from the end of 1941 until Japan surrendered unconditionally on 15 August 1945. During this period, GDP in most Southeast Asian countries fell by half; 4.4 million civilians died prematurely; severe shortages of food and goods affected almost all Southeast Asians; and many lived in fear of draconian military rule. The present book explores why and how this happened.