The war in the Pacific began in September 1931, as Japan, in a bid for overseas expansion, occupied Manchuria.  In July 1937, Japan invaded China, massacring nearly 400,000 civilians at Nanking.  By 1941, Japan had continued its overseas conquests with an invasion of French Indo-China, and an attack on British possessions in Indian, Burma, and the Pacific theatre.  Japan’s aggression led to sanctions by the United States against the nation on oil and steel.  In response, Japan decided to strike against the United States carrier fleet at Pearl Harbor, Hawaii.