During World War II, Japan invaded and occupied Vietnam, a nation on the eastern edge of the Indochina Peninsula in Southeast Asia that had been under French administration since the late 19th century. Inspired by Chinese and Soviet communism, Ho Chi Minh formed the Viet Minh, or the League for the Independence of Vietnam, to fight both Japan and the French colonial administration. Japan withdrew its forces in 1945, leaving the French-educated Emperor Bao Dai in control of an independent Vietnam. Ho’s Viet Minh forces rose up immediately, seizing the northern city of Hanoi and declaring a Democratic Republic of Vietnam (DRV) with Ho as president.
Seeking to regain control of the region, France backed Bao and set up the state of Vietnam (South Vietnam) in July 1949, with Saigon as its capital. Armed conflict continued until a decisive battle at Dien Bien Phu in May 1954 ended in French defeat by Viet Minh forces. The subsequent treaty negotiations at Geneva split Vietnam along the latitude known as the 17th parallel (with Ho in control in the North and Bao in the South) and called for nationwide elections for reunification to be held in 1956. In 1955, however, the strongly anti-communist Ngo Dinh Diem pushed Bao aside to become president of the Government of the Republic of Vietnam (GVN).
Vietnam War: U.S. Intervention Begins
With the Cold War intensifying, the United States hardened its policies against any allies of the Soviet Union, and by 1955 President Dwight D. Eisenhower had pledged his firm support to Diem and South Vietnam. With training and equipment from American military and police, Diem’s security forces cracked down on Viet Minh sympathizers in the south, whom he derisively called Viet Cong (or Vietnamese Communist), arresting some 100,000 people, many of whom were tortured and executed. By 1957, the Viet Cong and other opponents of Diem’s repressive regime began fighting back with attacks on government officials and other targets, and by 1959 they had begun engaging South Vietnamese Army forces in firefights.
In December 1960, Diem’s opponents within South Vietnam–both communist and non-communist–formed the National Liberation Front (NLF) to organize resistance to the regime. Though the NLF claimed to be autonomous and that most of its members were non-Communist, many in Washington assumed it was a puppet of Hanoi. A team sent by President John F. Kennedy in 1961 to report on conditions in South Vietnam advised a build-up of American military, economic and technical aid in order to help confront the Viet Cong threat. Working under the “domino theory,” which held that if one Southeast Asian country fell to communism, many would follow, Kennedy increased U.S. aid, though he stopped short of committing to a large-scale military intervention. By 1962, the U.S. military presence in South Vietnam had reached some 9,000 troops, compared with fewer than 800 during the 1950s.
Source: Vietnam War. (2012). The History Channel website. Retrieved 6:22, April 6, 2012, from http://www.history.com/topics/vietnam-war.