FDR was a fool for so doing.
General Patton had every single right to defy FDR's agreement to hand Czechoslovakia over to the Soviets.
FDR sold them out, and I am certain that had we told Russia to piss off, the USA could have kept CZ and SK free.
If only we had taken from the Soviets; Poland, Ukraine, Baltics, the Check Republics, besides all of Germany in the summer of 1945 the world would be a much better place.