What was the Soviet operation that invaded Japanese-held Manchuria in August 1945 called?

The Soviet operation that invaded Japanese-held Manchuria in August 1945 was called Operation August Storm.

The offensive began on 9 August 1945, when the Soviet Union attacked the Japanese-controlled Manchukuo and nearby territories. Soviet forces crossed the borders from several directions, including from Siberia and the Soviet Far East, and rapidly overwhelmed the Kwantung Army. The campaign also reached southern Sakhalin and the Kuril Islands.

The invasion formed part of the final Allied offensives against Japan. It followed the Soviet declaration of war and began at a critical moment, between the atomic bombing of Hiroshima and Japan’s acceptance of the Allied surrender terms. The destruction of Japan’s main continental army removed a major strategic option for continuing the war.

Operation August Storm is sometimes confused with Operation Downfall, the Allied plan for a possible invasion of Japan’s home islands. Downfall was never carried out. The Soviet offensive ended as Japan surrendered, although fighting and territorial operations continued in some areas afterward.