The name Viet Cong was an abbreviated name that came from the Vietnamese word for communist. The People’s Army was the regular army of North Vietnam. The Army of the Republic of Vietnam was the South’s official military force. The Khmer Rouge were Cambodia communists.

The Gulf of Tonkin Incident occurred in August 1964, when three North Vietnamese torpedo boats allegedly attacked the destroyer USS Maddox with machine guns and torpedoes. Only a single bullet struck the Maddox, which fired almost 300 shells at the attackers. Congress passed the Gulf of Tonkin Resolution which gave Johnson the authority to deploy more troops to Vietnam.

Operation Linebacker II was an attempt to bring the North Vietnamese back to negotiations. B-52 bombers attacked targets near Hanoi and Haiphong. More than 15,000 tons of bomb were dropped and more than 80 US aircraft were shot down.

The US experimented with various herbicides and defoliants at the end of World War II and during the 1950s. US armed forces sprayed 20 million gallons of Agent Orange in Vietnam, Laos, and Cambodia. The goal was to deprive insurgents of food and cover. Millions of Vietnamese civilians fell ill after being exposed to Agent Orange, which is also linked to health problems in US veterans.

Vietnamese insurgents often took refuge in Cambodia and Laos. They also used created trails in these countries to reinforce and resupply their troops in Vietnam. US forces bombed these areas in an effort to hinder the insurgents, even though Cambodia was neutral.

Soldiers from the 23rd Infantry entered the village of Mai Lai and massacred at least 347 Vietnamese civilians. Twenty-six soldiers were charged with criminal offenses, but only 2nd Lt. William Calley was convicted. He was sentenced to life in prison, but Nixon issued a pardon that reduced his sentence.

In 1969, more than 1,800 paratroopers and US marines attacked heavily fortified positions on Hamburger Hill (also known as Hill 937). The North Vietnamese defenders repulsed several assaults although US forces eventually captured the hill. More than 400 soldiers were killed or wounded, but the hill was eventually abandoned because it had little strategic importance.

The French created a garrison of more than 16,000 troops at Dien Bien Phu, including paratroopers, Legionnaires, and colonial tirailleurs. The Viet Minh insurgents surrounded the fortress and bombarded it with artillery. They used anti-aircraft guns to prevent resupply and reinforcement by air. Eventually, the Viet Minh overwhelmed the defenders and captured more than 11,000 French troops. The humiliating defeat forced the French to withdraw.

Diem took power after a fraudulent election in 1955. Diem was a Catholic and persecuted Buddhists — the majority religion in South Vietnam. The South Vietnamese army launched a coup against Diem in 1963 and he was assassinated.

President Dwight D. Eisenhower introduced the domino theory in 1954, when he said that knocking over one domino would cause the others to topple very quickly. Mutually assured destruction governed the use of nuclear weapons during the Cold War. Détente was a thaw in relations between the US/USSR. Rollback was an attempt to undermine communist regimes and replace them with US allies.

Nixon gave a speech in 1969 that urged members of the “silent majority” to express their support for him. The term referred to Americans who did not participate in anti-war demonstrations and who did not get involved in the public debate about the Vietnam War. Working class and middle class Americans in the suburbs and rural areas were thought to comprise the “silent majority.”

After protesters began burning their draft cards, Johnson signed a bill that made it a crime to destroy them. Anti-war protests spread across the country, and several hundred thousand marched on Washington D.C. in 1969 to voice their opposition to the war. Influential musicians wrote anti-war songs as well, including “Feel Like I’m Fixin’ to Die” (Country Joe & the Fish) and “Give Peace a Chance” (John Lennon).

In the Battle of AP Bac, more than 1,500 South Vietnamese troops attacked a Viet Cong force of about 350. The Viet Cong held their ground against infantry and APC assaults. It was a major victory for the Viet Cong and a humiliating defeat for the South Vietnamese.

The Battle of IA Drang was the first major battle between the United States Army and the People's Army of Vietnam. Helicopters inserted American forces into LZ X-RAY. US and North Vietnamese forces both suffered heavy losses, and each side claimed victory.

Although the Viet Cong initially achieved some success during the Tet Offensive, they sustained more than 100,000 casualties. Although the US secured a tactical victory, the surprise attack shocked the American public. They became increasingly skeptical of official reports on the Vietnam War, which led to a “credibility gap.”

President Nixon had announced the invasion of Cambodia on April 30, 1970. The next day, students at Kent State began protesting and tension rose until the National Guardsmen fired on students on May 4. Four students were killed and nine were injured, including one who became paralyzed.

President Nixon tried to shift the burden of fighting the war away from US forces and onto the shoulders of the South Vietnamese. This included providing more weapons and training to the South Vietnamese army.

Born in Germany in 1923, Kissinger and his family moved to the US in 1938. He joined the US Army during World War II and obtained a doctorate in political science. He became Secretary of State in Nixon’s administration and won the Nobel Peace Prize for negotiating the peace talks in 1973.

The peace talks provided for a temporary cease-fire that would allow for US troops to be withdrawn in 60 days. This effectively ended US involvement in the war. Although the agreement aimed for a peaceful reunification process, fighting between North and South Vietnam resumed after the last US troops left.

Fighting resumed shortly after the Paris Peace Talks of 1973. The North Vietnamese pushed towards Saigon but did not capture it until 1975. Even though the South Vietnamese army still had a large advantage in tanks, planes, and artillery, the soldiers were unwilling to stand and fight.

The South Koreans sent more than 300,000 soldiers to assist the South Vietnamese during the course of the war. That was the second largest contingent behind the Americans. The Australians sent 60,000 soldiers with more than 500 killed and 3,000 wounded. New Zealand sent 3,500 and more than 200 became casualties.

The Chinese claim to have sent more than $20 billion in aid to the North Vietnamese, as well as more than 300,000 soldiers. The Soviets sent $450 million in aid and 3,000 troops. Cuba sent at least one battalion of advisers and the North Koreans deployed two fighter squadrons with 200 pilots to North Vietnam.

Hue was the seat of the Nguyen dynasty between 1802 and 1945. More than 80 percent of the ancient city was destroyed during ferocious fighting in the Tet Offensive.

Westmoreland became an artillery officer and fought in World War II. He became a general in 1963 and took command of US forces in Vietnam. He used body counts to show that America was winning the war, but he was discredited by the surprising Tet Offensive of 1968. Abrams replaced him that same year. Westmoreland retired in 1972 and died in 2005.

Fulbright joined the US Senate in 1945. Although he voted for the Gulf of Tonkin Resolution, he had come to oppose the Vietnam War by 1966. He served in the Senate until 1974 and died in 1995. He also created the Fulbright program which is an international educational exchange.

Lodge fought during World War II and served twice in the US Senate. He became the US ambassador to South Vietnam in 1963 and thought Diem was too corrupt and ineffective. Lodge refused to talk to Diem during the coup and declined to protect him.

Cronkite became the host of the CBS Evening News in 1962. In 1968, he declared that the US should negotiate an end to the Vietnam War. He also covered the assassination of President John F. Kennedy. Cronkite retired in 1981 and died in 2009.

In 1967, Secretary of Defense Robert McNamara commissioned a study of American political and military involvement in Vietnam. Daniel Ellsberg was an analyst at the RAND Corporation and secretly copied the report. In 1971, the

The Degar were called the Montagnards by the French and many converted to Christianity. They often came into conflict with the Viet Cong, so the US Special Forces trained thousands to fight against their common enemy. Several thousand Montagnards resettled in North Carolina after the fall of Saigon.

Giap had commanded the Viet Minh and supervised the attack on Dien Bien Phu. He commanded the NVA throughout the war against the United States. However, he was blamed for the failure of the Easter Offensive in 1972. He retired in 1982 and died in 2013.

The Phoenix Program began in 1964 and continued until 1972. The CIA formed special teams called Provincial Reconnaissance Units that targeted suspected Viet Cong agents. If captured, Viet Cong agents faced torture. Almost 82,000 suspected Viet Cong agents were killed or captured. The program was exposed in 1970.

Cambodian Communists (Khmer Rouge) launched an insurgency in 1967 and seized power in 1975. The Laotian Communists (Pathet Lao) began fighting against the ruling monarchy in 1953 and eventually took power in 1975. Thailand was a monarchy but used American support to suppress the Thai communist party.