21. American Planners For an Invasion of Japan Expected Over a Million Casualties – and Tens of Millions Dead Japanese
Operation Downfall, the Allied invasion of Japan, was scheduled to commence with Operation Olympic in November of 1945, to secure the southern third of Kyushu, the southernmost of Japan’s main home islands. The seized territory would provide airbases for land-based aircraft, and serve as the staging area for an even bigger invasion. From Kyusho, Operation Coronet was to be launched in the spring of 1946, directed at Honshu, the largest and most populous of Japan’s home islands.
The operation was to commence with amphibious landings on three Kyushu beaches. However, as was discovered after the war, the Japanese had accurately predicted US intentions and landing sites. Japanese geography was such that the only viable beaches for large amphibious landings were the ones selected by Allied planners for operations Olympic and Coronet. Planners anticipated a million or more Allied casualties, plus tens of millions of Japanese casualties.