Poland, Bulgaria, and Romania were among the Eastern Bloc nations.
During the Cold War, the Eastern Bloc was the group of socialist countries in Central and Eastern Europe led by the Soviet Union and facing the Western Bloc, composed mainly of the United States and Western Europe.
The Eastern Bloc comprised the countries of Central and Eastern Europe, east of the Iron Curtain (with the exception of Yugoslavia), economically linked by the Council of Mutual Economic Assistance (COMECON) and militarily by the Warsaw Pact.