Vietnam War is conflict in Southeast Asia, primarily fought in South Vietnam between government forces aided by the United States and guerrilla forces aided by North Vietnam. The war began soon after the Geneva Conference provisionally divided (1954) Vietnam at 17° N lat. into the Democratic Republic of Vietnam (North Vietnam) and the Republic of Vietnam (South Vietnam). It escalated from a Vietnamese civil war into a limited international conflict in which the United States was deeply involved, and did not end, despite peace agreements in 1973, until North Vietnam's successful offensive in 1975 resulted in South Vietnam's collapse and the unification of Vietnam by the North.
For much of Vietnam's history it has been under foreign rule, primarily by the Chinese. In 1860, France began its domination of the area and had, by the late 19th century, implemented its colonization in a number of regions around the Gulf of Tonkin. During WWII, the Japanese government took control of much of the area and set up a puppet regime that was eventually forced out by the Vietnamese at the end of that war in 1945. After WWII and until 1955, France fought hard to regain their former territories in the region, but with a poorly organized army and little determination among the troops, their efforts soon collapsed. The French were finally defeated at Dien Bien Phu on the 8th of May 1954 by the communist general Vo Nguyen Giap. The French troops withdrew, leaving a buffer zone separating the North and South and set up elections in order to form a government in the South. The communist regime set up its headquarters in Hanoi under the leadership of Ho Chi Minh. Many North Vietnamese left the country and fled south where the self-proclaimed president, Ngo Dinh Diem had formed the Republic of Vietnam.
Between 1955 and 1960, the North Vietnamese with the assistance of the southern communist Vietcong, tried to take over the government in South Vietnam, and in November 1963 President Diem was overthrown and executed. The following year, the North Vietnamese began a massive drive to conquer the whole country aided by China and Russia. Fearing a communist takeover of the entire region, the United States grew more and more wary of the progress of Ho Chi Minh and the Vietcong.