The Supreme Commander for the Allied Powers was the title held by General Douglas MacArthur during the United States-led Allied occupation of Japan following World War II. It issued SCAP Directives to the Japanese government, aiming to suppress its "militaristic nationalism". The position was created at the start of the occupation of Japan on August 14, 1945. It was originally styled the Supreme Commander of the Allied Powers.

Unit 731 , short for Manchu Detachment 731 and also known as the Kamo Detachment and the Ishii Unit, was a covert biological and chemical warfare research and development unit of the Imperial Japanese Army that engaged in lethal human experimentation and biological weapons manufacturing during the Second Sino-Japanese War (1937–1945) and World War II. It killed an estimated 200,000 to 300,000 people. It was based in the Pingfang district of Harbin, the largest city in the Japanese puppet state of Manchukuo and had active branch offices throughout China and Southeast Asia.