American aid to the Soviet Union enabled the USSR to advance against the Nazis, it didn’t do as much to help them defend it. US and British aid made very little difference to the outcome of Stalingrad.
In any case, a Nazi conquest of the USSR was doomed from the outset, regardless of any outside help. Russia was too big, too cold and too populous.
It is also wrong to assume that the Soviets would have tried to conquer the entirety of Western Europe after conquering Germany, considering the fact that they were not willing to expend their energies in conquering Finland after 1944, especially if a lack of US help made the fight even more difficult and the Soviets were even more war-weary and exhausted than they actually were in 1945.
Given that the Nazi’s scoured conquered territories for food, so as not to “starve” their own population, I would think that food supplies would be of utmost importance to a fighting army. That said, I know the Soviets were tough. The Nazi’s could have easily won the war IF they had treated the civilian population with respect and offered inducements to the subject people’s there. Finland’s geographical location ensured their gravitation to Soviet influence, as much as Latvia’s and Lithuania’s. Even today, the Ukraine can hardly call itself a sovereign country due to Russian meddling. There’s a reason Patton wanted to fight on past Berlin.... The Eastern Europeans certainly paid a heavy price. Given the numbers of Soviet soldiers at Berlin in April 1945, they could easily have gone further (if unopposed) and that would have made life quite different for the remaining non communist countries on the continent.
I thought Finland kicked their ass. I guess the 59 divisions Germany had tied down in France, Belgium and the Netherlands wouldn’t have made a difference if they could have been assigned to the eastern front.