SCAP identified the Allied occupation authority led by Douglas MacArthur in Japan.
SCAP stood for Supreme Commander for the Allied Powers, the title used for General Douglas MacArthur and, by extension, the headquarters and occupation structure under his direction. MacArthur became the occupation’s central Allied administrator after Japan’s surrender in 1945.
SCAP supervised demilitarization, political reforms, economic measures, and the drafting of a new Japanese constitution. The occupation officially lasted from Japan’s surrender in 1945 until the Treaty of San Francisco took effect in 1952, although the United States retained control of Okinawa for longer.
The acronym can be confusing because wartime commands used similar abbreviations. SWPA referred to the Southwest Pacific Area, one of MacArthur’s wartime commands, while GHQ means General Headquarters and was used in several military contexts. SCAP specifically belongs to the occupation administration established after Japan’s surrender.