So your precious Serbs got punished by God too? Why should we shed a tear for them? And The Soviets that allied themselves with the Nazi's got what they deserved too. Since the US and England allied themselves with the Soviets I guess God should punish them as well?
This is the facts as it happened. Most of Eastern European countries minus Poland and the Czech side of that republic sided as allies in the attack on the USSR. They lost the war which cost the USSR 20-30 million lives.
You contend that after the war the Soviet army should have packed up their bags and went home afterward and act like all is forgiven? In what fantasy world?
But you want to play what should have happened? How the West should have played its hand? Ok if I was FDR or Churchill I would have said to Stalin - I wish you would not stay but we will not do anything to keep you out of Romania, Bulgaria, Hungry and Slovakia abd Eastern Germany/Austria. Yugoslavia and Greece and Poland are off limits since they were allied nations.