The West gave Stalin everything Hitler had promised him. All of Eastern Europe.
The REAL crime was the bromance of Socialist FDR and Communist pig Stalin. We shed our blood and treasure and gave EVERYTHING Stalin wanted even before the last American soldiers were buried and Hitler defeated.
It wasn’t an alliance, it was a plan to divide Poland between the Soviet Union and Nazi Germany.
The West was in no position to prevent it. Not that FDR minded that situation, mind . . .The US gave Stalin signal assistance, especially Studebaker trucks for mobility of the Red Army. But that was the price of keeping the USSR’s oil fields out of Hitler’s hands.
Granted that the US could have abrogated alliance with the USSR after the battle of Kursk, when the oil fields were no longer in danger - but if so, reduced Soviet pressure would have meant that the allied invasion of Normandy and into Germany would have faced German resistance from units which in fact stayed on the Ostfront.
And if you think that woulda been fun, you must have loved the Battle of the Bulge. Which Hitler launched precisely with units withdrawn from der Ostfront . . .