The 6th Canadian Infantry Division was originally scheduled to participate in this proposed Allied plan for the invasion of Japan near the end of World War II but the plan was abandoned after the Soviet invasion of which region? 
6th Canadian Infantry Division:  The 6th Division was to have been part of a proposed Commonwealth Corps, formed for a planned invasion of Japan, but was disbanded in 1945, after the war was ended by the bombing of Hiroshima and Nagasaki. Operation Downfall: Operation Downfall was the proposed Allied plan for the invasion of Japan near the end of World War II. Operation Downfall:  The planned operation was abandoned when Japan surrendered following the atomic bombings of Hiroshima and Nagasaki, the Soviet declaration of war and the Soviet invasion of Manchuria.
Manchuria