After World War II, France held Vietnam, which had a communist government led by Ho Chi Min. Most fighting took place in the northern part of the country in a series of guerilla style battles led by small skirmishing forces. These small bands, known as Viet Cong, were victorious against the France and helped create a North Vietnam that was Communist in 1954. By the mid 1960s, conflicts between the two Vietnams warped into open warfare, drawing in the United States openly and the USSR discreetly. The Viet Cong, even when representing a nation state, continued using guerilla tactics to frustrate the American troops.

The Paris Peace Accords of 1973 effectively ended American military involvement in the Vietnam War. It also provided a (temporary) peace between the forces of North and South Vietnam. For their role in the peace treaty, Henry Kissinger and Le Duc Tho were given the Nobel Peace Prize.

In 1973, the Paris Peace Accords formally ended direct American military involvement in the war in Vietnam. It was ignored privately by Richard Nixon and his administration, who continued to provide air support to the South Vietnamese forces. When Nixon was forced from office, the American government officially backed out of the Vietnam War and left the South Vietnamese to fall to conquest by the North Vietnamese. The famous "evacuation of Saigon," which occurred in April of 1975, was the final removal of all American personnel from Vietnam, just a day before the North Vietnamese entered and captured the capital of South Vietnam.

The Vietnam War spread across international borders into Cambodia and Laos, as both countries also had large numbers of communists alleged to be offering support to North Vietnam and the Viet Cong. Cambodia, in particular, was the target of many American bombing raids during the latter years of the Vietnam War.

The Tet Offensive was a surprise attack on the forces of the United States and South Vietnam by the forces of North Vietnam in 1968. The North Vietnamese were able to capture many cities and military bases in the South before the American forces regrouped and retook most of them. It was one of the largest and most significant military operations of the Vietnam War.

Agent Orange is the name given to a chemical dropped on the Vietnamese jungle by the American forces. Its intended purpose was to destroy leaves and reduce the tree cover, negating the guerrilla tactics of the Viet Cong; however, it ended up causing cancer and genetic mutations in many American soldiers and Vietnamese civilians.

Ho Chi Minh was initially a revolutionary who fought to overthrow the imperial French government in Vietnam. He was also a staunch communist, and he was the first Prime Minister of North Vietnam. During the Vietnam War, up to his death in 1969, he was president of North Vietnam and the leader of the Vietnamese Army and the Viet Cong.

The My Lai Massacre was the mass killing of approximately four hundred unarmed civilians by American soldiers in 1968. It was one of the more dramatic turning points for changing public opinion concerning the war in the United States. When the extent and depravity of the massacre emerged in America, many people joined the anti-war movement. 

During the Vietnam War, the Viet Cong fought for the forces of communist North Vietnam against the United States and the forces of South Vietnam. They fought a guerrilla war as well as a more traditional war and emerged victorious when the war ended in 1975.