NATO

The North Atlantic Treaty Organization is a military alliance of 32 countries in North America and Europe. Founded in 1949 in response to Soviet expansion, NATO commits its members to treat an armed attack on any one of them as an attack on all.

The North Atlantic Treaty was signed in Washington on April 4, 1949, by the United States, Canada, and ten European nations. It was the first peacetime military alliance the United States had ever joined, a sharp departure from George Washington's warning against permanent foreign entanglements. The treaty's most important provision is Article 5, which declares that an armed attack against one member shall be considered an attack against all, and that each member will assist the attacked country by taking such action as it deems necessary, including the use of armed force. NATO was founded to deter Soviet aggression in Europe. The Warsaw Pact, the Soviet counterpart, dissolved in 1991. NATO did not. It expanded eastward, adding former Soviet satellites in waves through the 1990s and 2000s. The alliance now has 32 members. Article 5 has been invoked exactly once in NATO's history. After the September 11, 2001 attacks on the United States, the allies declared that the attacks constituted an Article 5 event, and NATO forces fought alongside Americans in Afghanistan. Russia's invasion of Ukraine in 2022 prompted Finland and Sweden to join the alliance, ending decades of neutrality. Debates over NATO have recurred throughout its history. Conservatives have often pressed European members to spend more on their own defense, arguing that the alliance has long been subsidized by American taxpayers. Progressives have generally defended NATO as a cornerstone of the postwar order and a multiplier of American influence. The Marshall Plan and NATO together formed the twin pillars of American strategy in postwar Europe.