North Atlantic Treaty Organization

North Atlantic Treaty Organization (NATO), established under the North Atlantic Treaty (Apr. 4, 1949) by Belgium, Canada, Denmark, France, Great Britain, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, and the United States. Greece and Turkey entered the alliance in 1952, West Germany (now Germany) entered in 1955, and Spain joined in 1982. In 1999 the Czech Republic, Hungary, and Poland joined. Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia joined five years later, and Albania and Croatia joined in 2009, bringing the membership to 28. NATO maintains headquarters in Brussels, Belgium.

The treaty, one of the major Western countermeasures against the threat of aggression by the Soviet Union during the cold war, was aimed at safeguarding the freedom of the North Atlantic community. Considering an armed attack on any member an attack against all, the treaty provided for collective self-defense in accordance with Article 51 of the United Nations Charter. The treaty was also designed to encourage political, economic, and social cooperation. The organization was reorganized and centralized in 1952, and has undergone subsequent reorganizations.

NATO's highest organ, the North Atlantic Council, may meet on several levels—heads of government, ministers, or permanent representatives. The council determines policy and supervises the civilian and military agencies; NATO's secretary-general chairs the council. Under the council is the Military Committee, which may meet at the chiefs of staff or permanent representative level. Its headquarters in Washington, D.C., has representatives of the chiefs of staff of all member countries. France withdrew from the Military Committee from 1966 to 1995 while remaining a member of the council, and did not decide to return to NATO's military command in 2009.

NATO is now divided into two commands. Allied Command Operations is headed by the Supreme Allied Commander Europe (SACEUR). SACEUR directs NATO forces and, in time of war, controls all land, sea, and air operations. Allied Command Transformation, with headquarters at Norfolk, Va., is responsible for making recommendations on the strategic transformation of NATO forces in the post-cold-war era.

In the 1990s, with the collapse of the Soviet Union and the Warsaw Treaty Organization, NATO's role in world affairs changed, and U.S. forces in Europe were gradually reduced. Many East European nations sought NATO membership as a counterbalance to Russian power, but they, along with other European and Asian nations (including Russia), initially were offered only membership in the more limited Partnership for Peace, formed in 1994. Twenty-two countries now belong to the partnership, which engages in joint military exercises with NATO. NATO is not required to defend Partnership for Peace nations from attack. In 2002, NATO and Russia established the NATO-Russia Council, through which Russia participates in NATO discussions on many nondefense issues.

NATO has increasingly concentrated on extending security and stability throughout Europe, and on peacekeeping efforts in Europe and elsewhere. NATO air forces were used under UN auspices in punitive attacks on Serb forces in Bosnia in 1994 and 1995, and the alliance's forces were subsequently used for peacekeeping operations in Bosnia. NATO again launched air attacks in Mar.-June, 1999, this time on the former Yugoslavia following following the breakdown of negotiations over Kosovo. In June, 1999, NATO was authorized by the United Nations to begin trying to restore order in the province, and NATO peacekeeping forces entered Kosovo. In Aug., 2003, NATO assumed command of the international security force in the Kabul area in Afghanistan, which by 2006 had expanded to include some 31,000 troops (including 11,000 Americans) deployed throughout Afghanistan; and in Oct., 2003, a NATO rapid-response force was established.

The membership of many NATO nations in the increasingly integrated European Union (EU) has led to tensions within NATO between the United States and those EU nations, particularly France and Germany, who want to develop an EU defense force, which necessarily would not include non-EU members of NATO. In 2008 disagreements between Greece and Macedonia over the latter's name led Greece to veto an invitation to Macedonia to join. The same year, Georgia and Ukraine were promised eventual membership but not given any timetable; Russia had objected strongly to their becoming NATO members.

in full North Atlantic Treaty Organization

International military alliance created to defend western Europe against a possible Soviet invasion. A 1948 collective-defense alliance between Britain, France, The Netherlands, Belgium, and Luxembourg was recognized as inadequate to deter Soviet aggression, and in 1949 the U.S. and Canada agreed to join their European allies in an enlarged alliance. A centralized administrative structure was set up, and three major commands were established, focused on Europe, the Atlantic, and the English Channel (disbanded in 1994). The admission of West Germany in 1955 led to the Soviet Union's creation of the opposing Warsaw Treaty Organization, or Warsaw Pact. France withdrew from military participation in 1966. Since NATO ground forces were smaller than those of the Warsaw Pact, the balance of power was maintained by superior weaponry, including intermediate-range nuclear weapons. After the Warsaw Pact's dissolution and the end of the Cold War in 1991, NATO withdrew its nuclear weapons and attempted to transform its mission. It involved itself in the Balkan conflicts of the 1990s. Article 5 of the North Atlantic Treaty stated that an attack on one signatory would be regarded as an attack on the rest. This article was first invoked in 2001 in response to the terrorist September 11 attacks against the U.S. Additional countries joined NATO in 1999 and 2004 to bring the number of full members to 26. In 2009 France announced its plan to rejoin NATO's integrated military command.

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List of ambassadors and permanent representatives to the North Atlantic Treaty Organization (North Atlantic Council)

Ambassador	Start of Term	End of Term	Appointed by
Arnold Danford Patrick Heeney	1952	1952	Louis St. Laurent
Leolyn Wilgress	1953	1958	Louis St. Laurent
Jules Léger	1958	1962	John Diefenbaker
George Ignatieff	1962	1966	John Diefenbaker
Charles Ritchie	1966	1967	Lester B. Pearson
Ross Campbell (Canadian diplomat)	1967	1972	Lester B. Pearson
Arthur Menzies	1972	1976	Pierre Trudeau
Joseph Hardy	1976	1980	Pierre Trudeau
John Halstead (Canadian diplomat)	1980		Pierre Trudeau
James Taylor	1982	1985	Pierre Trudeau
Gordon Smith (Canadian diplomat)	1985		Brian Mulroney
James Bartleman	1990	1994	Brian Mulroney
Admiral John R. Anderson	1994	1997	Jean Chrétien
David Wright	1997		Jean Chrétien
Jean-Pierre Juneau	2003		Jean Chrétien