The North Atlantic Treaty Organization (NATO, /ˈneɪtoʊ/; French: Organisation du traité de l'Atlantique nord, OTAN), also called the North Atlantic Alliance, is an intergovernmental military alliance between 30 member states – 28 European and two North American. Established in the aftermath of World War II, the organization implements the North Atlantic Treaty, which was signed in Washington, D.C., on 4 April 1949.