Before 1990 , there were radical political changes in the Eastern Bloc that had to do with the liberalization of the Eastern Bloc 's authoritarian systems and the erosion of political power in the pro-Soviet governments in nearby Poland and Hungary .
In 1989 , a series of radical political changes occurred in the Eastern Bloc , associated with the liberalization of the Eastern Bloc 's authoritarian systems and the erosion of political power in the pro-Soviet governments in nearby Poland and Hungary .
Berlin Wall