North Atlantic Treaty Organization Is Formed Summary

  • Last updated on November 10, 2022

Twelve democracies established the North Atlantic Treaty Organization, or NATO, as an association for mutual defense against the Soviet Union.

Summary of Event

On April 4, 1949, the United States and eleven other nations (Belgium, Canada, Denmark, France, the United Kingdom, Iceland, Italy, Luxembourg, the Netherlands, Norway, and Portugal) signed a treaty of alliance establishing the North Atlantic Treaty Organization (NATO), committing the signatories to the principle of common security on a regional basis. By joining, the United States under President Harry S. Truman took a precedent-shattering step; it had never before concluded a military alliance in peacetime with any European state. Participation in NATO meant that the United States had modified one of its oldest principles, which stemmed from the advice of George Washington and Thomas Jefferson: to avoid entangling alliances. [kw]North Atlantic Treaty Organization Is Formed (Apr. 4, 1949) [kw]Treaty Organization Is Formed, North Atlantic (Apr. 4, 1949) North Atlantic Treaty Organization Cold War;mutual defense agreements North Atlantic Treaty Organization Cold War;mutual defense agreements [g]Europe;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Belgium;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Canada;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Denmark;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]France;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Iceland;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Italy;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Luxembourg;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Netherlands;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Norway;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Portugal;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]Sweden;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]United Kingdom;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [g]United States;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [c]Cold War;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [c]Diplomacy and international relations;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] [c]Organizations and institutions;Apr. 4, 1949: North Atlantic Treaty Organization Is Formed[02910] Acheson, Dean Marshall, George C. [p]Marshall, George C.;Cold War Stalin,Joseph [p]Stalin, Joseph;Cold War Truman, Harry S. [p]Truman, Harry S.;Cold War Vandenberg, Arthur Hendrick

The genesis for such an alliance emerged from the Truman administration’s containment policy, with the fundamental objective of opposing Soviet expansionist efforts in Europe after World War II. The United States had committed itself in the 1947 Truman Doctrine Truman Doctrine (1947) to assisting European nations facing civil war or external threats from the Soviet Union, led by Joseph Stalin.

Also in 1947, Secretary of State George C. Marshall proposed the more ambitious European Recovery Program. Economic aid through this costly effort, better known as the Marshall Plan, greatly assisted the European economy after the program began in 1948. There was widespread belief in the United States, however, that Europe’s full economic and psychological recovery World War II (1939-1945)[World War 02];reconstruction would not be possible until Europeans believed themselves safe from the threat of the Soviet Red Army. Thus, military security was essential for continued economic recovery.





Several major events in 1948 revealed the widening Cold War in Europe. A communist coup d’état in Czechoslovakia, the Soviet blockade of Berlin (lasting into 1949), and other Soviet actions convinced the Truman administration of the need for more extensive, long-term U.S. involvement in Europe. Despite appeals from European leaders for the creation of a common front, however, Truman was not sufficiently confident of public and congressional support to move directly toward an alliance. In June, the Senate approved the Vandenberg Resolution Vandenberg Resolution (1948) , named for Senator Arthur Hendrick Vandenberg, the major proponent of the movement for a bipartisan foreign policy. The Senate vote of 64-4 declared support for U.S. participation in regional arrangements for “continuous and effective self-help and mutual aid.” This pronouncement was interpreted by some as an attempt to limit presidential power in foreign affairs rather than as a sincere expression of support for collective security. Only after the presidential election of 1948 and cautious discussions with the principal European nations did the Truman administration act to move the United States away from its traditional isolationism.

In March, five European nations—Great Britain, France, Belgium, the Netherlands, and Luxembourg—signed the Brussels Pact, a fifty-year defensive alliance. Its terms obligated the signatories to come to the aid of any member attacked by an aggressor. The Brussels Pact nations invited the United States to participate, but there were numerous obstacles to concerted action at that time, even though the Vandenberg Resolution showed U.S. interest in a mutual security system. In January, 1949, more positive support was expressed in Truman’s inaugural address, which promised that the United States would contribute to the defense of friendly nations.

The United States began negotiations with a number of European states, with the aim of creating a cooperative system of military security against the presumed Soviet threat to Western Europe. These discussions were criticized by some people in the United States and especially by communist authorities in Moscow. They accused the United States of undercutting the United Nations and jeopardizing world peace by forming a bloc of states for aggressive purposes. The United States answered this accusation by pointing out that article 51 of the U.N. Charter allowed for regional defense pacts, and that the proposed alliance clearly was defensive in character.

Dean Acheson, who succeeded Marshall as secretary of state in early 1949, believed that the United States should look to military and diplomatic arrangements to meet the communist challenge rather than rely upon the institutional procedures of the United Nations, which could be blocked by a Soviet veto. Negotiations achieved the desired objective of an expanded association of democratic states. In ceremonies in Washington, D.C., on April 4, the North Atlantic Treaty was signed by representatives of twelve nations—Belgium, Canada, Denmark, France, Iceland, Italy, Luxembourg, the Netherlands, Norway, Portugal, the United States, and the United Kingdom. They reaffirmed their support of the United Nations, vowed to cooperate in the maintenance of the stability and well-being of the North Atlantic region, and promised to work together for collective defense and the preservation of peace and general security.

Although the pact bound its members to settle international disputes by peaceful means, article 5 stated that “the Parties agree that an armed attack against one or more of them in Europe or North America shall be considered an attack against them all.” Any attack would be met by armed force, if necessary. Each member state was permitted to adopt its own response to aggression after consultation with its allies. The treaty provided for the establishment of the NATO council, on which each of the signatory states was to be represented. The council created a defense committee and other departments to develop measures for the nations’ common defense. No signatory was committed absolutely to go to war, but the treaty was a powerful moral commitment to aid members threatened by aggression. The treaty was to be in effect for at least twenty years and could be renewed.

Senate hearings on the North Atlantic Treaty, while not endangering its chances of ratification by the United States, resulted in sometimes bitter debate concerning the wisdom of U.S. involvement. Prominent national political figures, such as Senator Robert A. Taft Taft, Robert A. , warned against the United States assuming major long-term responsibilities. These discussions revealed that the Truman administration could not anticipate all the military implications of the new alliance. Nevertheless, on July 21 the Senate approved the North Atlantic Treaty by a vote of 82-13. Eleven of the thirteen who voted “no” were Republicans, but both Republicans and Democrats supported the treaty. By late August, following ratification by member governments, NATO officially formed.


The adoption of the pact demonstrated the signatories’ willingness to make military commitments for their common security. Although NATO was never used in actual combat with the Soviet Union, its formation illustrated the unity of spirit and dedication of its Western democracies. Members who entered NATO later included Greece and Turkey (1952), West Germany (1955), and Spain (1981). NATO succeeded in fulfilling its primary purpose of creating a viable military counterweight to Soviet power.

With the collapse of communist systems in the states of Eastern Europe in 1989, followed by the disintegration of the Soviet Union in 1991, the relevance and functions of NATO had to be reconsidered. Despite the apparent end of the Cold War, all member governments agreed that the organization still served the primary objective of promoting stability within Europe, even as new problems (such as the Yugoslav civil war) appeared on the horizon. That conflict blossomed in the mid-1990’s, eventually provoking a NATO response, primarily in the form of air strikes against Serbian forces, and NATO participation in the Dayton Peace Accord follow-up implementation.

When civil war broke out in Kosovo, NATO members circumvented the United Nations, making the decision to bomb Serbia for its refusal to sign an ultimatum to allow NATO peacekeepers to deploy in Kosovo and to permit Kosovo’s autonomy. NATO forces were prominent in the post-bombing period of Kosovo reconstruction. This event was unprecedented in NATO history, and required the organization to rethink its mission as a defense alliance. No NATO country was under attack; rather, NATO intervened in the domestic affairs of a nonmember state on humanitarian grounds.

NATO subsequently took yet another unprecedented step by undertaking military operations outside Europe, when in August, 2003, it assumed responsibility for military and security operations in Afghanistan after the United States toppled the Taliban regime for its assumed complicity in the September 11, 2001, terrorist attacks in the United States. Clearly, NATO has broken the mold and redefined itself.

Several East European states formerly associated with the Soviet Union applied during the 1990’s for NATO membership, fearful of the possibility of a resurgence of Russian expansionism. Eventually, nine former communist countries of Eastern Europe or former Soviet Socialist Republics were admitted to NATO, after the organization decided to move forward with enlargements. These countries included Bulgaria, the Czech Republic, Hungary, Poland, Romania, and Slovakia, as well as the former Soviet Socialist Republics of Estonia, Latvia, and Lithuania. Slovenia, once a part of the former Yugoslavia, was also admitted, bringing NATO’s membership to twenty-six nations in the first decade of the twenty-first century. Three other countries from the Balkans region are under consideration for membership, including Albania, Croatia, and Macedonia. Moscow has viewed NATO enlargement with suspicion, but has been in no position to prevent it. North Atlantic Treaty Organization Cold War;mutual defense agreements

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Acheson, Dean. Present at the Creation: My Years in the State Department. New York: Norton, 1969. Memoirs of the U.S. secretary of state at the time of NATO’s formation.
  • citation-type="booksimple"

    xlink:type="simple">Feis, Herbert. From Trust to Terror: The Onset of the Cold War, 1945-1950. New York: Norton, 1970. Provides a detailed account of the issues and crises during the Cold War in the later 1940’s.
  • citation-type="booksimple"

    xlink:type="simple">Kaplan, Lawrence S. NATO and the United States: The Enduring Alliance. New York: Twayne, 1988. A solid survey of the United States’s relationship with its NATO partners.
  • citation-type="booksimple"

    xlink:type="simple">Osmanczyk, Edmund Jan. The Encyclopedia of the United Nations and International Agreements. Edited by Anthony Mango. 4 vols. 3d ed. Philadelphia: Taylor & Francis, 2003. Provides brief but detailed entries on a variety of international organizations and agreements at the global level.
  • citation-type="booksimple"

    xlink:type="simple">Rose, Clive. Campaigns Against Western Defense: NATO’s Adversaries and Critics. New York: St. Martin’s Press, 1985. An unusual perspective on NATO that assesses its opponents.
  • citation-type="booksimple"

    xlink:type="simple">Schmidt, Gustav, ed. A History of NATO: The First Fifty Years. New York: Palgrave, 2001. A comprehensive three-volume history of NATO, from its formation in 1949 through the end of the twentieth century. Highly recommended.
  • citation-type="booksimple"

    xlink:type="simple">Sherwen, Nicholas, ed. NATO’s Anxious Birth: The Prophetic Vision of the 1940’s. New York: St. Martin’s Press, 1985. Diverse topical essays discuss the formative period of the alliance.
  • citation-type="booksimple"

    xlink:type="simple">Truman, Harry. Memoirs: Years of Trial and Hope, 1946-1952. Garden City, N.Y.: Doubleday, 1956. The president’s account of the events and negotiations leading to the Western alliance in the late 1940’s.
  • citation-type="booksimple"

    xlink:type="simple">United Nations Treaty Collection. Treaty Handbook. Available at An excellent resource on the international treaty process. An online handbook provided by the Treaty Section of the U.N. Office of Legal Affairs.
  • citation-type="booksimple"

    xlink:type="simple">Urwin, Derek W. The Community of Europe: A History of European Integration Since 1945. New York: Longman, 1995. A compact, yet detailed history of the various organizations carrying out European integration after World War II.
  • citation-type="booksimple"

    xlink:type="simple">Vandenberg, Arthur H. The Private Papers of Senator Vandenberg. Edited by Arthur H. Vandenberg, Jr. Boston: Houghton Mifflin, 1952. Observations of a prominent supporter of Western defense.

Soviets Take Control of Eastern Europe

Churchill Delivers His Iron Curtain Speech

Truman Doctrine

Marshall Plan Provides Aid to Europe

Soviet Bloc States Establish Council for Mutual Economic Assistance

Stalin and Mao Pen a Defense Pact

United Nations General Assembly Passes the Uniting for Peace Resolution

United States Inaugurates Mutual Security Program

Western European Union Is Established

Nonaligned Movement Meets

Categories: History