Stalin, Mao and Pol Pot didn't even try to get socialism to work. They were murderous dictators. Show me where in socialist philosophy it says that socialist countries can be run by murderous dictators. Chavez and Castro were both seriously undermined by US foreign policy. They both got a lot of things wrong and I won't make excuses for that. But, as exercises in socialism, Venezuela and Cuba didn't stand a chance, though both those leaders tried against the odds to get some things right.