America didn't have the ability to take on Germany. We needed time to build a military that could accomplish that task. Nor could we afford to allow Germany to have access to a conquered Russia. Our priority was saving England. Supporting the Russian's kept Germany busy and forced them to spend their military on the Eastern front.
The problem with your analysis is the USA helped a tyrannical regime that had a long history of murdering and enslaving their own people and whom tyrannically imposed an ideology entirely antithetic to American values. Supporting evil to contain another evil is ignorant and what resulted is proof it was ignorance.
It must be remembered that due to FDR being completely co-opted by American commie traitors in his administration, he did not merely provide support to the stinking bastard Stalin, he flooded the USSR with military and industrial hardware that could have been used by MacArthur to support our troops and allies in the Pacific against the Japanese. Thus saving American and allied lives. What FDR did was traitorous and he should have been impeached for it...but then he did so many impeachable things, this is but one of many.
Secondly, we never should have warred against Germany. They never attacked us. But again, due to the commies controlling Stalin's stooge in the White House, they forced the war with Germany not to protect America, but to protect Stalin. Most disgusting.
it is a STAIN on our nation that we helped erradicate nazism from the face of the earth!
Not to the fringe element here.