North Atlantic Treaty Organization

The North Atlantic Treaty Organization (NATO) is both an intergovernmental political consultative organization and a military alliance. First envisioned in the wake of the Second World War, NATO was founded by the 12 signatory states of the Washington Treaty (also known as the North Atlantic Treaty) on April 4, 1949. The treaty commits its members to mutual consultation and, if necessary, the option of collective military force in protecting the North Atlantic area—the territories of the individual member states, including their territories, personnel, vessels, and aircraft in the Mediterranean Sea and north of the Tropic of Cancer.

Although the alliance’s primary purpose during the Cold War era was to ensure collective defense of its members by deterring Soviet aggression, in the post–Cold War security environment, the ...