The news reel ("Soviet fights back! Russia stop Hitler!") concentrates on fighting between Nazi Germany and the Soviet Union before U.S. entry into the war in December 1941. The events described here were part of Operation Barbarossa, Hitler's plan to invade and conquer the Soviet Union. You can read about that plan here (from the Holocaust Education and Archive Research Team) and here (from The Atlantic Magazine).
The pre-Cold War admiration of the Soviet soldiers makes it a nice exercise in changing point-of-view (Nazis are described as "treacherous" while Soviet citizens are seen smiling in support of their troops) and context (the United States and the Soviet Union were wartime allies at that point in World War II).