Which planned operation would have attacked Japan’s Kantō Plain near Tokyo in spring 1946?

Operation Coronet was the planned Allied attack on Japan’s Kantō Plain near Tokyo in spring 1946.

Coronet was the second phase of Operation Downfall, following the proposed invasion of southern Kyūshū under Operation Olympic. The Kantō Plain contained Tokyo and was considered the decisive objective for bringing Japan’s government and military centers under Allied control.

The operation was tentatively scheduled to begin on 1 March 1946. The U.S. First and Eighth Armies were expected to make major landings, with additional Commonwealth forces potentially joining the campaign.

Coronet was never launched because Japan surrendered in August 1945. Its name is sometimes confused with Olympic because both were components of Downfall. Japan’s corresponding defensive plan was called Operation Ketsugō, which anticipated an all-out effort to repel the expected invasion.