Member states of NATO

The North Atlantic Treaty Organization (NATO) is an international military alliance consisting of 32 member states from Europe and North America. It was established at the signing of the North Atlantic Treaty on 4 April 1949. Of the 32 member countries, 30 are in Europe and two are in North America. Between 1994 and 1997, wider forums for regional cooperation between NATO and its neighbours were set up, including the Partnership for Peace, the Mediterranean Dialogue initiative, and the Euro-Atlantic Partnership Council.

All members have militaries, except for Iceland, which does not have a typical army (but it does have a coast guard and a small unit of civilian specialists 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 states. Three more members joined between 1952 and 1955, and a fourth joined in 1982. Since the end of the Cold War, NATO has added 16 more members from 1999 to 2024. Article 5 of the treaty states that if an armed attack occurs against one of the member states, it shall be considered an attack against all members, and other members shall assist the attacked member, with armed forces if necessary. Article 6 of the treaty limits the scope of Article 5 to the islands north of the Tropic of Cancer, the North American and European mainlands, the entirety of Turkey, and French Algeria, the last of which has been moot since July 1962. Thus, an attack on Hawaii, Puerto Rico, French Guiana, the Falkland Islands, Ceuta or Melilla, among other places, would not trigger an Article 5 response.

NATO recognizes Bosnia and Herzegovina, Georgia, and Ukraine as aspiring members as part of their Open Door enlargement policy.

NATO was established on 4 April 1949 via the signing of the North Atlantic Treaty (Washington Treaty). The 12 founding members of the Alliance were: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom, and the United States.

The various allies all signed the Ottawa Agreement, which is a 1951 document that acts to embody civilian oversight of the Alliance.

Current membership consists of 32 countries. In addition to the 12 founding countries, four new members joined during the Cold War: Greece and Turkey (1952), West Germany (1955) and Spain (1982). Additionally, NATO experienced territorial expansion during this period without adding new member states when Zone A of the Free Territory of Trieste was annexed by Italy in 1954, and the territory of the former East Germany was added with the reunification of Germany in 1990. NATO further expanded after the Cold War, adding the Czech Republic, Hungary, and Poland (1999); Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, and Slovenia (2004); Albania and Croatia (2009); Montenegro (2017); North Macedonia (2020); Finland (2023); and Sweden (2024). Of the territories and members added between 1990 and 2024, all except for Finland and Sweden were either formerly part of the Warsaw Pact (including the formerly Soviet Baltic states) or territories of the former Yugoslavia. No countries have left NATO since its founding, although France withdrew from NATO unified command between 1966 and 2009.

Since the accession of Sweden on 7 March 2024, the North Atlantic Treaty Organization covers a total area of 27,580,492 km² (10,648,887 sq mi).

On October 2025, during a meeting between President Donald Trump and Finnish president Alexander Stubb, Trump suggested throwing Spain out of NATO. He called the country "Laggard", as it fails to meet the budget agreement of 5% GDP defense expenditure, like all other members. He was quoted saying: "You people are gonna have to start speaking to Spain, . . . You have to call them and find [out] why are they a laggard."