Member states of NATO members and three former Yugoslav republics) from 12 March 1999 to 5 June 2017. NATO has added new members seven times since its founding in 1949, and since 2017 NATO has had 29 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, joined later by West Germany (in 1955) and Spain (in 1982). In 1990, with the reunification of Germany, NATO grew to include the former country of East Germany. Between
Enlargement of NATO Enlargement of NATO Enlargement of the North Atlantic Treaty Organization (NATO) is the process of including new member states in NATO. NATO is a military alliance of twenty-seven European and two North American countries that constitutes a system of collective defense. The process of joining the alliance is governed by Article 10 of the North Atlantic Treaty, which allows only for the invitation of "other European States", and by subsequent agreements. Countries wishing to join have to meet certain requirements and complete a multi-step process involving political dialogue and military integration. The accession process is overseen by the North Atlantic