The 1954 Geneva agreement provided for a cease-fire between communist and anti-communist nationalist forces, the temporary division of Vietnam at approximately the 17th parallel, provisional northern (communist) and southern (noncommunist) zone governments, and the evacuation of anti-communist Vietnamese from northern to southern Vietnam. The agreement also called for an election to be held by July 1956 to bring the two provisional zones under a unified government. However, the South Vietnamese Government refused to accept this provision. On October 26, 1955, South Vietnam declared itself the Republic of Vietnam. 
A frustrated Ho Chi Minh eventually decided to militarily move into South Vietnam with his Viet Minh (later Viet Cong) as the increasingly unpopular US controlled government employed stronger tactics to maintain the South Vietnamese people under Diem. In retaliation the US sent 'advisers' to help Diem keep the situation under control before stepping up to a full scale ground war. The war was the longest in American history, lasting approximately 16 years. It was also the first war fought by America in which the stated military goals of the Americans were not met. The turning point was the Tet Offensive where the North Vietnamese launched simultaneous large scale attacks on multiple targets. Military a failure, it succeeded in the realm of perceptions in America since it showed a much more resilient and stronger Vietnamese enemy than that which had been believed by the American public. It is now widely agreed that it is the first war America actually lost failing to win the hearts and minds of both the Vietnamese and the people back home. America left the war in 1973 under an arrangement that was supposed to keep South Vietnam free from the Communist north, but in 1975 the north invaded and quickly conquered the country. Today Vietnam has a communist government.
Opposition to the Vietnam War
The Vietnam War is remembered as creating massive opposition in the United States. Millions of Americans, including some known as hippies, were opposed to the Vietnam War. They felt that they had been lied to by the government and that the war was unnecessary. Others objected for reasons such as a commitment to pacifism. This opposition inspired such songs as "The I Feel Like I'm Fixing to Die Rag," by Country Joe McDonald, "Give Peace a Chance," by John Lennon, "Run Through the Jungle," by Creedence Clearwater Revival, and "War," by Edwin Starr. This opposition also manifested itself in the form of protests. One of the most famous protests of this era occurred at Kent State University in Ohio, during which four students were shot and killed by the Ohio State National Guard following several days of rioting and the firebombing of the ROTC building. The shooting was later determined to be justified when a federal court dismissed the case against the eight guardsmen indicted.
It wasn't until the Reagan era that popular culture, and society, began to embrace Vietnam veterans as heroes by creating characters like John Rambo and John "Hannibal" Smith.
- Larry Berman, Perfect Spy: The Incredible Double Life of Pham Xuan An, Time Magazine (Smithsonian Books/HarperCollins, 2007). 
- SIGINT and the Fall of Saigon, April 1975.
- "Secrecy, Freedom and Empire: Lessons for Today from Vietnam and the Pentagon Papers".
- Vietnam War.