Warsaw Pact
Organizations
in wich Poland participates or participated

Warsaw Pact

Uklad Warszawski (Polish) , the Warsaw Pact or Warsaw Treaty Organisation, officially named the Treaty of Friendship, Co-operation and Mutual Assistance (Russian: Договор о дружбе, отрудничестве и взаимной помощи), was an organisation of Central and Eastern European communist states. It was established on May 14, 1955 in Warsaw, Poland to counter the alleged threat from the NATO alliance.

Member states: Soviet Union, Poland, East Germany, Czechoslovakia, Bulgaria, Hungary, Romania, Albania (withdrew its support in 1961 over ideological differences, formally left in 1968)

On 25 February 1991, the Warsaw Pact was declared disbanded at a meeting in Hungary. On 12 March 1999, the former Warsaw Pact members and successor states Hungary, Poland and the Czech Republic
Governor's Palace, now presidential palace,         
were the Warsaw Pact was signed.

joined NATO. Bulgaria, Estonia, Latvia, Lithuania, Romania, and Slovakia followed suit in March 2004.
More information

Polonica stamps:

Albania 1976, 08 VIII
Bulgaria 1980, 14 V
Czechoslovakia 1980, 06 V
German Dem. Rep. 1970, 01 X
German Dem. Rep. 1975, 06 V
German Dem. Rep. 1980, 13 V
German Dem. Rep. 1985, 14 V
Hungary 1975, 15 XII
Soviet Union 1975, 16 IV
Soviet Union 1980, 14 V
Soviet Union 1985, 14 V