Vietnam War History. Lasting from 1955 to 1975, the Vietnam war engulfed the Southeast Asian country of Vietnam as well as its neighboring countries, Cambodia and Laos. It resulted in several million deaths, most of whom were Vietnamese civilians. The conflict began during the 1950s when the struggle between the country's communist northern part and the anti-communist south escalated. The United States began its military involvement in an effort to back the South's effort to quell the communist onslaught, which, at the height of the Cold War, was feared to promote the spread of communist ideology and influence worldwide. During the war, about 500,000 US troops were dispatched to Southeast Asia, about 58,000 of whom were killed. The conflict ended in 1975 with the fall of Saigon and the victory of North Vietnam.