Russia was at least as evil as Germany, they fought Germany because their ally turned on them, rattler against rattler.
We don’t have to pretend that they were a noble good guy, fighting the good fight.
Stalin would have started the war by 1943, when he figured the Red Army would be strong enough to go on the offensive.
He counted on a War in the West, that would bleed the German, French and British armies dry. Turns out France falling so quickly was a blessing in disguise.