What was the Soviet operation in Manchuria commonly called during Japan’s final days of World War II?

The Soviet operation in Manchuria was commonly called Operation August Storm.

The invasion began on 9 August 1945, when the Soviet Union attacked Japanese-held Manchuria and the Japanese puppet state of Manchukuo. Soviet forces also moved against Mengjiang in Inner Mongolia. The campaign is formally known as the Manchurian Strategic Offensive Operation.

Its timing was crucial. Soviet forces entered the war against Japan between the atomic bombings of Hiroshima and Nagasaki. Japan’s leaders had hoped the Soviet Union might mediate a conditional peace, but the Soviet declaration of war destroyed that diplomatic strategy. The rapid defeat of the Kwantung Army became one of the major pressures behind Japan’s decision to surrender.

Operation August Storm is sometimes confused with Operation Downfall, the proposed Allied invasion of Japan. Downfall was never carried out because Japan surrendered before the planned invasion. Operation Olympic, meanwhile, was the proposed first phase of Downfall, aimed at southern Kyushu.

Fighting did not instantly stop everywhere. The Kwantung Army formally surrendered on 16 August, while some combat continued until the September surrender ceremony.