Hungarian Revolution: Imre Nagy announces Hungary's neutrality and withdrawal from the Warsaw Pact. Soviet troops begin to re-enter Hungary, contrary to assurances by the Soviet government. János Kádár and Ferenc Münnich secretly defect to the Soviets.

The Hungarian Revolution of 1956, also known as the Hungarian Uprising, was an attempted countrywide revolution against the government of the Hungarian People's Republic (1949–1989) and the policies caused by the government's subordination to the Soviet Union (USSR). The uprising lasted 15 days before being crushed by Soviet tanks and troops on 7 November 1956. Thousands were killed or wounded, and nearly a quarter of a million Hungarians fled the country.

Imre Nagy was a Hungarian communist politician who served as Chairman of the Council of Ministers of the Hungarian People's Republic from 1953 to 1955. In 1956 Nagy became leader of the Hungarian Revolution of 1956 against the Soviet-backed government, for which he was sentenced to death and executed two years later. He was not related to previous agrarianist Prime Minister Ferenc Nagy.

The Warsaw Pact (WP), formally the Treaty of Friendship, Cooperation and Mutual Assistance (TFCMA), was a collective defense treaty signed in Warsaw, Poland, between the Soviet Union and seven other Eastern Bloc socialist republics in Central and Eastern Europe in May 1955, during the Cold War. The term "Warsaw Pact" commonly refers to both the treaty itself and its resultant military alliance, the Warsaw Pact Organisation (WPO). The Warsaw Pact was the military complement to the Council for Mutual Economic Assistance (Comecon), the economic organization for the Eastern Bloc states.

The Soviet Ground Forces was the land warfare service branch of the Soviet Armed Forces from 1946 to 1992. It was preceded by the Red Army.