The NATO (North Atlantic Treaty Organization) is an international alliance that consists of 28 member states from North America and Europe. It was established at the signing of the North Atlantic Treaty on 4 April 1949. Article Five of the treaty states that if an armed attack occurs against one of the member states, it should be considered an attack against all members, and other members shall assist the attacked member, with armed forces if necessary.[1]

Of the 28 member countries, two are located in North America (Canada and the United States) and 25 are European countries while Turkey is in Eurasia. All members have militaries, although Iceland does not have a typical army (it does, however, have a military coast guard and a small unit of soldiers for NATO operations). Three of NATO's members are nuclear weapons states: France, the United Kingdom, and the United States. NATO has 12 original founding member nation states and from 18 February 1952 to 1 April 2009 it added 16 more member nations.

NATO has added new members six times since its founding in 1949, and since 2009 NATO has had 28 members. Twelve countries were part of the founding of NATO: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States. In 1952, Greece and Turkey became members of the Alliance. In 1990, with the reunification of Germany, NATO grew to include the former country of East Germany. Between 1994 and 1997, wider forums for regional cooperation between NATO and its neighbors were set up, including the Partnership for Peace, the Mediterranean Dialogue initiative and the Euro-Atlantic Partnership Council. In 1997, three former Warsaw Pact countries, Hungary, the Czech Republic, and Poland, were invited to join NATO. After this fourth enlargement in 1999, the Vilnius group of The Baltics and seven East European countries formed in May 2000 to cooperate and lobby for further NATO membership. Seven of these countries joined in the fifth enlargement in 2004. Albania and Croatia joined in the sixth enlargement in 2009.

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Member states of NATO - Wikipedia, the free encyclopedia