Warsaw Pact

The Warsaw Pact (formally, the Treaty of Friendship, Co-operation, and Mutual Assistance, sometimes, informally WarPac, akin in format to NATO was a collective defense treaty among Soviet Union and seven Soviet satellite states in Central and Eastern Europe in existence during the Cold War. The Warsaw Pact was the military complement to the Council for Mutual Economic Assistance (CoMEcon), the regional economic organization for the communist states of Central and Eastern Europe.

Members

 * Albania/People's Republic of Albania
 * Bulgaria/People's Republic of Bulgaria
 * Czechoslovakia/Czechoslovak Republic
 * East Germany/German Democratic Republic
 * Hungary/Hungarian People's Republic
 * Poland/Polish People's Republic
 * Romania/Romanian People's Republic
 * Soviet Union/Union of Soviet Socialist Republics

More information on the Wikipedia page