Formosa (Taiwan). In June 1950 at the beginning of the Korean War, President Truman ordered the U.S. Seventh Fleet to prevent Chinese Communist attacks upon Formosa and Chinese Nationalist operations against mainland China.
China. Naval units evacuated U.S. civilians and military personnel from the Tachen Islands.
Egypt. A marine battalion evacuated U.S. nationals and other persons from Alexandria during the Suez crisis.
Lebanon. Marines were landed in Lebanon at the invitation of its government to help protect against threatened insurrection supported from the outside. The President’s action was supported by a Congressional resolution passed in 1957 that authorized such actions in that area of the world.
The Caribbean. 2d Marine Ground Task Force was deployed to protect U.S. nationals during the Cuban crisis.
Thailand. The 3d Marine Expeditionary Unit landed on May 17, 1962 to support that country during the threat of Communist pressure from outside; by July 30 the 5,000 marines had been withdrawn.
Cuba. On October 22, President Kennedy instituted a “quarantine” on the shipment of offensive missiles to Cuba from the Soviet Union. He also warned the Soviet Union that the launching of any missile from Cuba against any nation in the Western Hemisphere would bring about U.S. nuclear retaliation on the Soviet Union. A negotiated settlement was achieved in a few days.
Laos. From October 1962 until 1975, the United States played an important role in military support of anti-Communist forces in Laos.
Congo. The United States sent four transport planes to provide airlift for Congolese troops during a rebellion and to transport Belgian paratroopers to rescue foreigners.
Vietnam War. U.S. military advisers had been in South Vietnam for a decade, and their numbers had been increased as the military position of the Saigon government became weaker. After citing what he termed were attacks on U.S. destroyers in the Tonkin Gulf, President Johnson asked in August 1964 for a resolution expressing U.S. determination to support freedom and protect peace in Southeast Asia. Congress responded with the Tonkin Gulf Resolution, expressing support for “all necessary measures” the President might take to repel armed attack against U.S. forces and prevent further aggression. Following this resolution, and following a Communist attack on a U.S. installation in central Vietnam, the United States escalated its participation in the war to a peak of 543,000 military personnel by April 1969.
Dominican Republic. The United States intervened to protect lives and property during a Dominican revolt and sent more troops as fears grew that the revolutionary forces were coming increasingly under Communist control.
Congo. The United States sent three military transport aircraft with crews to provide the Congo central government with logistical support during a revolt.
Cambodia. U.S. troops were ordered into Cambodia to clean out Communist sanctuaries from which Viet Cong and North Vietnamese attacked U.S. and South Vietnamese forces in Vietnam. The object of this attack, which lasted from April 30 to June 30, was to ensure the continuing safe withdrawal of American forces from South Vietnam and to assist the program of Vietnamization.
Evacuation from Cyprus. United States naval forces evacuated U.S. civilians during hostilities between Turkish and Greek Cypriot forces.
Instances of Use of United States Armed Forces Abroad, 1798-2010
Congressional Research Service