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
Member states of NATO Member states of NATO NATO (the North Atlantic Treaty Organization) is an international alliance that consists of 29 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. Of the 29 member countries, two are located in North America (Canada and the United States) and 27 are European