North Atlantic Treaty Organization (NATO abbreviated in English and NATO in French) is a political-military alliance established in 1949 by North Atlantic Treaty signed in Washington on 4 April 1949. Currently comprises 19 countries in Europe and North America.
Alliance of Independent States was formed, interested in maintaining peace and defending their independence through political solidarity and a corresponding defensive military force able to deter and, if necessary, to meet all likely forms of aggression against them or Member States. Initially, these countries were: Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, United Kingdom, Norway, Portugal, Netherlands and USA. On 18 February 1952, joined the treaty Greece and Turkey, and on 6 May 1955, the FRG joined NATO.
Since its establishment, the basic idea of the alliance, maintained for over 50 years, was that of achieving a common defense, credible and effective. In this respect, Article 5 of the Treaty specified: "The Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against all and therefore, if he such an armed attack occurs, each of them individually or collectively exercising his right to self-defense recognized by Article 51 of the Charter of the United Nations, will assist the Party or Parties attacked by taking accordingly, individually and in concert with other parties, those measures to be deemed necessary, including the use of armed force, to restore and maintain the security of the North Atlantic area. "