Stalin and Russian contributions to the invasion of Poland and collusion [gently in the movie, referred to as a "non-aggression pact"] with NAZI Germany, play no part - erased from history.
That is, a tragic omission of the hell, the conspiracy of the communists and nationalizing socialists.
The numbers of murdered people, will never be blamed on the Soviets. As far as the world knows, Germans killed millions, and Stalin saved them.
History rarely reflects reality.