Member states of NATO

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).

The current members and their dates of admission are listed below.

Special arrangements

The three Nordic countries which joined NATO as founding members, Denmark, Iceland and Norway, chose to limit their participation in three areas: there would be no permanent peacetime bases, no nuclear warheads and no Allied military activity (unless invited) permitted on their territory. However, Denmark allowed the US to maintain an existing base, Thule Air Base (now Pituffik Space Base), in Greenland.

From the mid-1960s to the mid-1990s, France pursued a military strategy of independence from NATO under a policy dubbed "Gaullo-Mitterrandism". Nicolas Sarkozy negotiated the return of France to the integrated military command and the Defence Planning Committee in 2009, the latter being disbanded the following year. France remains the only NATO member outside the Nuclear Planning Group and unlike the United States and the United Kingdom, will not commit its nuclear-armed submarines to the alliance.

As of June 2026, three additional states have formally informed NATO of their membership aspirations: Bosnia and Herzegovina, Georgia, and Ukraine.

• NATO members agreed at the 2008 Bucharest Summit that Georgia and Ukraine "will become members of NATO in the future".
• Bosnia and Herzegovina was invited by NATO to join the Membership Action Plan (MAP) in April 2010.

No state has ever withdrawn from NATO, but some dependencies of member states have not requested membership after becoming independent:

• Cyprus (independence from the United Kingdom in 1960)
• Algeria (independence from France in 1962)
• Malta (independence from the United Kingdom in 1964)

The following list is constructed from The Military Balance, published annually by the International Institute for Strategic Studies.

The defence spending of the United States is more than double the defence spending of all other NATO members combined. (Note that this is total U.S. defense spending, not spending specifically for NATO) Criticism of the fact that many member states were not contributing their fair share in accordance with the international agreement by then US president Donald Trump caused various reactions from American and European political figures, ranging from ridicule to panic. While NATO members have committed to spending at least 2% of their Gross Domestic Product (GDP) on defence, most of them did not meet that goal in 2023.

Pew Research Center's 2016 survey among its member states showed that while most countries viewed NATO positively, most NATO members preferred keeping their military spending the same. The response to whether their country should militarily aid another NATO country if it were to get into a serious military conflict with Russia was also mixed. Roughly half or fewer in six of the eight countries surveyed say their country should use military force if Russia attacks a neighboring country that is a NATO ally. And at least half in three of the eight NATO countries say that their government should not use military force in such circumstances. The strongest opposition to responding with armed force is in Germany (58%), followed by France (53%) and Italy (51%). More than half of Americans (56%) and Canadians (53%) are willing to respond to Russian military aggression against a fellow NATO country. A plurality of the British (49%) and Poles (48%) would also live up to their Article 5 commitment. The Spanish are divided on the issue: 48% support it, 47% oppose.

YouGov, a market research company that is mainly active in the UK also hosts a regularly updated public opinion polling for NATO. As of 6 January 2025, 45% of UK citizens strongly support NATO, 31% Tend to support NATO, 18% Don't know, 3% Tend to oppose and 3% Strongly oppose. Older people (65+) Strongly support NATO at 59%, whilst in younger demographics (18-24), Tend to support ranks the highest at 34%, and Don't know is at 33%.

A 2025 poll found that support for NATO membership was 52%, compared to the 66% of Slovenians who voted for NATO membership in a referendum in 2003.