The Warsaw Pact is abolished.

The Warsaw Pact, formally known as the Treaty of Friendship, Cooperation and Mutual Assistance, was a collective defence treaty signed in Warsaw, Poland among the Soviet Union and seven Soviet satellite states of Central and Eastern Europe in May 1955, during the Cold War. The Warsaw Pact was the military complement to the Council for Mutual Economic Assistance, the regional economic organization for the socialist states of Central and Eastern Europe. The Warsaw Pact was created in reaction to the integration of West Germany into NATO in 1955 per the London and Paris Conferences of 1954, but it is also considered to have been motivated by Soviet desires to maintain control over military forces in Central and Eastern Europe.

The Warsaw Pact was established as a balance of power or counterweight to NATO; there was no direct confrontation between them. Instead, the conflict was fought on an ideological basis and in proxy wars. Both NATO and the Warsaw Pact led to the expansion of military forces and their integration into the respective blocs. Its largest military engagement was the Warsaw Pact invasion of Czechoslovakia in August 1968, which, in part, resulted in Albania withdrawing from the pact less than a month later. The Pact began to unravel in its entirety with the spread of the Counter-Revolutions of 1989 through the Eastern Bloc, beginning with the Solidarity movement in Poland and its electoral success in June 1989.

East Germany withdrew from the Pact following reunification with West Germany in 1990. On 25 February 1991, the Pact was declared at an end at a meeting of defence and foreign ministers from the six remaining member states in Hungary. The USSR itself was dissolved in December 1991, although most of the former Soviet republics formed the Collective Security Treaty Organization shortly thereafter. Throughout the following 20 years, the seven Warsaw Pact countries outside the USSR each joined NATO, as did the three Baltic states that had been part of the Soviet Union.