What was the code name for the proposed Allied invasion of Japan in late 1945?

Operation Downfall was the code name for the proposed Allied invasion of Japan in late 1945.

The plan was never carried out because Japan surrendered before the invasion began. Operation Downfall consisted of two planned stages: Operation Olympic, the proposed invasion of Kyushu scheduled for November 1945, and Operation Coronet, the planned invasion of Honshu near Tokyo scheduled for March 1946.

Allied planners expected fierce resistance. Japan was preparing military units and civilians for a decisive homeland defense, while the United States was assembling troops, ships, aircraft, and supplies for the operation. Casualty estimates varied widely and were politically controversial, but planners understood that an invasion could be extremely costly.

The atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war, and the Japanese government’s decision to surrender eliminated the need for Downfall. Operation Overlord, by contrast, was the 1944 Allied invasion of Normandy in Europe. The similar-sounding names are a frequent source of confusion, but they referred to entirely different theaters and campaigns.