In December 1941 Japan, already at war with China, attacked British, Dutch and American territories in Asia and the Pacific. By June 1942, Japanese conquests encompassed a vast area of south-east Asia and the western Pacific. Under Japanese occupation, prisoners of war and enslaved civilians were forced to work for their captors in harsh and often inhuman conditions.
A series of land battles were fought in China, Burma and New Guinea. Although Japan achieved early successes, its resources were overstretched. In contrast, America was able to mobilise huge economic resources to intensify its efforts, beginning with amphibious landings in the Pacific. Tokyo and other Japanese cities suffered unprecedented destruction by conventional bombing. Finally, after atomic bombs were dropped on Hiroshima and Nagasaki, and following Soviet intervention, Japan surrendered in August 1945.
Japanese occupation hastened the end of European colonialism and the rise of communism in Asia, while post-war American occupation transformed Japanese society.