Why did communism in the Soviet Union collapse?
Among many other things was rampant internal corruption.
What challenges did former Soviet allies such as Yugoslavia face as a result of the collapse of the Soviet Union?
Identify three most unreal aspects of communism that you think led to the collapse of Soviet Union and decline of the communism in the world community?
No, the collapse of the USSR does not actually prove that communism doesn't work, any more than the failure of Joe's Fish and Chips proves that restaurants don't work. The failure of the Soviet Union and its satellite states is just one example in which a paranoid version of communism didn't work. It may well be that it is possible to do it better. Although I offer no guarantees.