NATO (North Atlantic Treaty Organisation)

The North Atlantic Treaty Organisation (NATO, or the Atlantic Alliance) is an intergovernmental military alliance founded by the North Atlantic Treaty, also known as the Treaty of Washington, signed on 4 April 1949. NATO’s stated purpose is to guarantee the freedom and security of its members through political and military means.

NATO’s structure broadly comprises two arms:

a civilian, administrative arm, which includes:
- the North Atlantic Council, made up of NATO countries’ permanent delegations,
- a nuclear planning group,
- international staff at NATO headquarters in Brussels; and
a military arm, which comprises:
- NATO’s Military Committee, which advises the North Atlantic Council on military strategy,
- Allied Command Operations, responsible for NATO military activities,
- Allied Command Transformation, which takes care of defence planning and capability development.

Headquartered in Brussels, NATO has 31 members following successive enlargements:

April 1949: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United Kingdom and the United States (the 12 founding members);
February 1952: Greece and Turkey;
May 1955: West Germany (following the reunification of Germany in 1990, the country as a whole became a member);
May 1982: Spain;
March 1999: the Czech Republic, Hungary and Poland;
March 2004: Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia and Slovenia;
1 April 2009: Albania and Croatia;
5 June 2017: Montenegro;
27 March 2020: North Macedonia;
4 April 2023: Finland.

With 22 member countries in common, the EU and NATO have worked particularly closely together since 2003 (with the conclusion of the Berlin Plus Agreement giving the EU, under certain conditions, access to NATO assets and capabilities), building on the cooperation on defence previously developed between NATO and the now-defunct Western European Union.

Recent examples of NATO and the EU working closely together include:

in the area of maritime security, the European Union Naval Force Mediterranean Operation IRINI, which cooperated with NATO’s Sea Guardian operation;
in the Middle East, where the EU is engaged as a non-military partner and all 27 Member States involved as partners, while NATO has been supporting the Global Coalition against Daesh.

EU Member States’ commitments and cooperation under the common security and defence policy are consistent with their commitments under NATO.