After WW2 practically the whole Eastern Europe was under the dominance of Soviet Union.
Creation of Warsaw Pact made that influence even stronger.
Still, in some countries there were opened rebellion against this strict regimes.
The best examples for this are Hungary (1956) and Czech Republic (1968).
Although the revolution was unsuccessful, it showed that repression will not be easily accepted. At the end just thirty years later communist regime was overthrown.
