Which operation was the planned first phase of the canceled Allied invasion of Japan?

Operation Olympic was the planned first phase of the canceled Allied invasion of Japan.

Olympic was intended to begin on November 1, 1945, with landings on southern Kyushu, Japan’s southernmost main island. The objective was to seize territory and airfields that could support a later invasion of the Kanto Plain near Tokyo. That second phase was called Operation Coronet.

Both operations formed the larger plan known as Operation Downfall. Olympic would have involved a huge naval and air force effort, with Allied planners preparing multiple landing areas and staging bases. Japanese planners anticipated the attack and developed Operation Ketsugo to defend Kyushu and the other home islands.

Japan surrendered before Olympic began. The decision followed the atomic bombings, the Soviet entry into the war against Japan, and the emperor’s acceptance of the Potsdam Declaration. Operation Olympic is therefore a major example of a military operation that was extensively planned but never executed.