Just as some Americans need occasionally to be reminded that the war did not start on 7 December 1941, some Russians apparently need to be reminded that it didn't start on 22 June, 1941, either. The brutal crushing of Poland was something that nobody should need to be reminded of, after all. Or its predation of Jews by both sides.
In fact, the Soviet Union was an ally of all of the major participants of that war at one point or another. I just alluded to the Molotov/Ribbentrop Pact but let us not forget the Soviet-Japanese Neutrality Pact of April, 1941, an agreement that the Japanese honored even while its merchant marine was being slaughtered by the U.S. More than half the U.S. supplies to the Soviets came through Vladivostok unmolested, even on U.S.-flagged ships. No, none of that is forgotten.