North Atlantic Treaty

The North Atlantic Treaty, also known as the Washington Treaty, was signed in Washington, D.C., on 4 April 1949 by the United States, Canada and ten Western European states, and it forms the legal foundation of the North Atlantic Treaty Organization, the military alliance established to implement it. Its central provision, Article 5, states that an armed attack against one or more of the treaty's parties in Europe or North America shall be considered an attack against them all, committing signatories to take such action as they deem necessary, including the use of armed force, to restore and maintain security. Drafted in the early years of the Cold War as a collective response to concerns about Soviet expansion in Europe, the treaty created a peacetime military alliance without precedent for the United States, which had traditionally avoided binding defense commitments outside the Western Hemisphere, and it remains the founding legal instrument of NATO, the organization it created, which has since expanded well beyond its original twelve signatories.