NATO
The North Atlantic Treaty Organization (NATO) was founded on April 4, 1949, with the signing of the North Atlantic Treaty in Washington, D.C. Its founding members were the United States, Canada, Britain, France, Belgium, the Netherlands, Luxembourg, Denmark, Norway, Iceland, Portugal and Italy. Headquartered in Brussels, Belgium, the military alliance adopts a system of collective defense whereby its member states agree to mutual defense in response to an attack by any external party.
In 1966, French President Charles de Gaulle announced that France would withdraw from NATO's military structure and remove its forces from NATO's integrated military command, while remaining a political member of the alliance.
After the fall of the Berlin Wall in 1989, the organization became drawn into the Balkans, while building better links with former potential enemies to the east. A number of former Warsaw Pact states joined the alliance in 1999 and 2004. On April 1 this year, its membership was enlarged to 28 with the entry of Albania and Croatia. Since the September 11 terrorist attacks in 2001, NATO has attempted to refocus itself on new challenges and deployed troops to Afghanistan as well as trainers to Iraq.
Current French President Nicolas Sarkozy carried out a major reform of France's military position, leading to its return to full membership on April 4, 2009.
Warsaw Pact
The Soviet Union, Czechoslovakia, Bulgaria, Hungary, East Germany, Poland, Romania and Albania signed the Treaty of Friendship, Cooperation and Mutual Assistance in Warsaw, Poland, on May 14, 1955, in response to West Germany's entry into NATO. The treaty gave birth to the military alliance Warsaw Treaty Organization, also known as the Warsaw Pact. The Moscow-based alliance was the European Communist bloc's counterpart to NATO during the Cold War. It was officially dissolved at a meeting in Prague on July 1, 1991.