The term Eastern Bloc referred to the former Communist states of Eastern and Central Europe , including the countries of the Warsaw Pact , along with Yugoslavia and Albania , which were not aligned with the Soviet Union after 1948 and 1960 respectively . The Eastern Bloc refers to the former communist states of Eastern and Central Europe , especially the Soviet Union and its satellites in the Warsaw Pact . Prior to 1948 , sources referred to Yugoslavia as part of the Eastern Bloc , though many considered it no longer a part after Yugoslavia broke with Soviet policy in the Tito-Stalin split .