And Kiev was once part of Poland, so what’s your point....lands change hands over time due to war, WWII was no different.
You said ‘forcing Germans’ back to Germany was fine.
But Koenigsberg was German. So it wasn’t for Stalin about ‘forcing Germans to Germany’, it was about gobbling up more land for himself, taking over parts of Germany and Poland and all of Eastern Europe.
That was the legacy of FDR.