You ascribe to the Communists — and Putin’s Russia as well as China are still run by communists, albeit modified since mid-20th century, — a quality they don’t possess: consistency. Within the span of three years Stalin was a friend of Hitler and a mortal foe of Hitler; he was a foe of capitalist America and its best friend. When the cards fall right for them, the Russians and the Chinese will become best buddies again. Remember China and Russia very much complement each other in macroeconomic terms.
You guys need to learn history. Read a ‘Diplomacy’ by Kissinger to start with. Stalin was never a friend of Hitler. He was actually the first to fight Axis as early as mid-1930 in Spain backing Republicans against a German-backed national socialist element. It was pretty much as Korea 20 years later with a Nazy Germany instead of US. He has sent hordes of ‘advisors’ and shipped thousands of advanced aircraft including SB medium bombers (faster than any opposing German fighter at the time), Rata fighters - a Mig-15 of the earlier 1930s (a revolutionary all-metal monoplane, retractable gear, 1000+hp etc).
By late 1930s Stalin was taking directly on the Japanese in Mongolia and Northern China.
In fact Stalin was desperately seeking an alliance against Axis by 1938 but both France and UK told him to go pound sand.
Molotov-Ribbentropp pact was nothing but a way to get some time to rearm before inevitable war against Hitler. Finland, Poland, East Romania and Baltic States were occupied by Stalin as a buffer zones for that same reason.
BTW, to think modern Russia is run by commies is to ignore reality. Communist Party of Russia is mostly a laughing stock there, in a class of Illinois Nazis or something.