Independent national politics made feasible with the perestroika and liberal glasnost policies revealed shortcomings and failures (i.e. of the soviet-type economic planning model) and have induced institutional collapse of the Communist government in the USSR in 1991. From 1989 to 1991, Communist governments were overthrown in Albania, Poland, Hungary, Czechoslovakia, East Germany, Romania, Bulgaria, Yugoslavia, and the Soviet Union. As the last acts of the Cold War were playing out, several Warsaw Pact states (Poland, Czechoslovakia, and Hungary) participated in the US-led coalition effort to liberate Kuwait in the Gulf War. On 25 February 1991, the Warsaw Pact was declared disbanded at a meeting of defence and foreign ministers from remaining Pact countries meeting in Hungary. On 1 July 1991, in Prague, the Czechoslovak President Václav Havel formally ended the 1955 Warsaw Treaty Organization of Friendship, Cooperation and Mutual Assistance and so disestablished the Warsaw Treaty after 36 years of military alliance with the USSR. The USSR disestablished itself in December 1991. Structure 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. Although an apparently similar collective security alliance, the Warsaw Pact differed substantially from NATO. De jure, the eight-member countries of the Warsaw Pact pledged the mutual defense of any member who would be attacked; relations among the treaty signatories were based upon mutual non-intervention in the internal affairs of the member countries, respect for national sovereignty, and political independence. However, de facto, the Pact was a direct reflection of the USSR's authoritarianism and undisputed domination over the Eastern Bloc, in the context of the so-called Soviet Empire, which was not comparable to that of the United States over the Western Bloc. All Warsaw Pact commanders had to be, and have been, senior officers of the Soviet Union at the same time and appointed for an unspecified term length: the Supreme Commander of the Unified Armed Forces of the Warsaw Treaty Organization, which commanded and controlled all the military forces of the member countries, was also a First Deputy Minister of Defence of the USSR, and the Chief of Combined Staff of the Unified Armed Forces of the Warsaw Treaty Organization was also a First Deputy Chief of the General Staff of the Soviet Armed Forces. On the contrary, the Secretary General of NATO and Chair of