Historically, the Soviet Union's fall, as dramatic as it was, was a surprisingly bloodless affair with the attempt by Chechnya to declare independence from Russia and the conflict between Armenia and Azerbaijan being notable exceptions. Your challenge is, with a POD after March 5, 1953, for the Soviet Union to collapse in a bloody civil war much like the former Yugoslavia did historically without WW3 breaking out. Bonus points if this collapse of the USSR leads to either the usage of nuclear weapons or an American intervention into the former USSR.