Together with the U.S. atomic bombings of Hiroshima on Aug. 6, 1945 and Nagasaki three days later, the Soviet Union's entry into war against Japan -- also on Aug. 9 -- served as a coup de grace, rendering further meaningful resistance by Japanese forces impossible.
The large-scale military campaign under Marshal A.M. Vasilevsky, Supreme Commander of Soviet Forces in the Far East, has left bitter legacies that fester to this day between Moscow and Tokyo.
First, there was the postwar internment of some 575,000 Japanese -- not only from Manchuria, but also from North Korea, southern Sakhalin and the Kuril Islands. Of those, about 70,000 died, including 55,000 in continental Russia and 15,000 in Sakhalin and the Kurils. Second, sovereignty of the islands Japan calls its Northern Territories remains in dispute and Russia continues to occupy them.