The Warsaw Treaty Organization of Friendship, Cooperation, and Mutual Assistance (1955–1991), more commonly referred to as the Warsaw Pact, was a mutual defense treaty between eight communist states of Eastern Europe in existence during the Cold War. The founding treaty was established under the initiative of the Soviet Union and signed on 14 May 1955, in Warsaw. The Warsaw Pact was the military complement to the Council for Mutual Economic Assistance (CoMEcon), the regional economic organization for the communist states of Eastern Europe. The Warsaw Pact was a Soviet military response to the integration of West Germany into NATO in 1955, per the Paris Pacts of 1954.

In the West, the Warsaw Treaty Organization of Friendship, Cooperation, and Mutual Assistance is often called the Warsaw Pact military alliance; abbreviated WAPA, Warpac, and WP. Elsewhere, in the former member states, the Warsaw Treaty is known as:

The Warsaw Treaty’s organization was two-fold: the Political Consultative Committee handled political matters, and the Combined Command of Pact Armed Forces controlled the assigned multi-national forces, with headquarters in Warsaw, Poland. Furthermore, the Supreme Commander of the Unified Armed Forces of the Warsaw Treaty Organization was also a First Deputy Minister of Defense of the USSR, and the head of the Warsaw Treaty Combined Staff also was a First Deputy Chief of the General Staff of the Armed Forces of the USSR. Therefore, although ostensibly an international collective security alliance, the USSR dominated the Warsaw Treaty armed forces.

Warsaw (Polish: Warszawa [varˈʂava] ( listen); see also other names) is the capital and largest city of Poland. It is located on the Vistula River, roughly 260 kilometres (160 mi) from the Baltic Sea and 300 kilometres (190 mi) from the Carpathian Mountains. Its population in 2010 was estimated at 1,716,855 residents with a greater metropolitan area of 2,631,902 residents, making Warsaw the 10th most populous city proper in the European Union. The area of the city covers 516.9 square kilometres (199.6 sq mi), while the city's agglomeration covers 6,100.43 square kilometres (2,355.39 sq mi).

Warsaw is an Alpha- global city, a major international tourist destination and an important economic hub in Central Europe. It is also known as the "phoenix city" because it has survived many wars throughout its history. Most notably, the city had to be painstakingly rebuilt after the extensive damage it suffered from World War II, during which 80% of its buildings were destroyed. On 9 November 1940 the city was awarded Poland's highest military decoration for heroism, the Virtuti Militari, for the Siege of Warsaw (1939).