Vietnam War Era: 1955–1975

Gulf of Tonkin Incident and Key Battles of the Vietnam War

Gulf of Tonkin Incident and the Gulf of Tonkin Resolution

After the Gulf of Tonkin incident, Congress granted President Johnson broad authority to "repel any armed attack" against U.S. forces.

The assassination of Ngo Dinh Diem brought more disunity and a new, but shaky, military dictatorship. As South Vietnam faltered, North Vietnam launched an offensive and sent army units to the South. The Soviets and Chinese supplied weapons and personnel to the offensive. By 1964 President Johnson and his advisors discussed launching American military strikes in the North, and the Pentagon formed a plan for air strikes on specific northern targets. They also discussed seeking a congressional resolution that would give Johnson wide-ranging authority to conduct the war. Johnson decided to wait until after his first election in 1964 to make a decision about striking North Vietnam.

Events in August 1964 changed Johnson's plans. The following points give a timeline of those events and their results.

  • August 2, 1964: The destroyer USS Maddox entered the Tonkin Gulf on an electronic surveillance patrol of North Vietnam. Three North Vietnamese torpedo boats fired on the USS Maddox. The Maddox drove off the attackers with aid from aircraft on a U.S. carrier also in the Gulf of Tonkin.
  • August 3, 1964: The USS Maddox resumed its patrol and was joined by another destroyer, the USS Turner Joy. The day passed without incident.
  • August 4, 1964: That night the ships experienced poor weather conditions and limited visibility. Both ships sent messages they were being attacked by torpedo boats. The captain of the Maddox, however, sent a later message urging caution about the accuracy of the earlier reports because of the weather. The Johnson administration—even though it had been told of the uncertainty of the second attack—chose to believe the second attack had occurred.
  • August 5, 1964: The United States ordered a series of limited air raids against North Vietnamese naval bases, and President Johnson asked the U.S. Congress for the authority to deal with future threats in Vietnam by whatever means he deemed necessary.
  • August 7, 1964: The Gulf of Tonkin Resolution, a resolution passed by the Senate and House of Representatives in response to the Tonkin incident, received a nearly unanimous congressional vote. In the resolution, President Johnson was given the authority to "take all necessary measures to repel any armed attack against the forces of the United States and to prevent further aggression." Congress itself never declared war. The war was conducted under presidential authority with Congress's financial backing.

Gulf of Tonkin Incident, August 1964

Two U.S. destroyers patrolling the Gulf of Tonkin reported being fired on by torpedo boats. Although the attack may actually have been the effects of bad weather, the United States launched retaliatory airstrikes on North Vietnam.

Key Battles, Events, and Outcomes of the Vietnam War

Even after key battles, territory often changed hands and both sides claimed victory in the Vietnam War.
Date Event Result
August 7, 1964 Gulf of Tonkin Resolution passed by Congress. The United States escalated its participation in South Vietnam.
March 2, 1965–October 31 1968 Operation Rolling Thunder The United States bombs targets in North Vietnam to force it to cease supporting Viet Cong guerrillas in South Vietnam.
November 14–17, 1965 The Battle of la Drang Valley is fought in South Vietnam's Central Highlands, the location of a major supply route into the south for the People's Army of Vietnam (PAVN), the communist North Vietnamese forces. It is the first major battle between the United States and PAVN. Both sides claim victory. The United States introduces a new tactic called "air mobility" to deploy forces and uses aerial bombardment.
November 2, 1967, and March 25, 1968 President Johnson secretly meets with the "Wise Men," a group of prestigious U.S. leaders. The "Wise Men" advise the president to use the press to paint U.S. involvement in the war in a more positive light. Later, they recommend the administration seek peace terms.
January 30–March 28, 1968 The Tet Offensive begins with a surprise attack by Viet Cong and PAVN forces on 13 cities in South Vietnam on Tet, the traditional Vietnamese celebration of the New Lunar Year. By the following day, over 100 towns and cities are under attack. Viet Cong and the PAVN suffer heavy losses and are driven back. This is a turning point for many Americans who are convinced the United States cannot win in South Vietnam.
January 31–March 2, 1968 Battle of Hue, part of the Tet Offensive The Viet Cong and PAVN invade Hue, an ancient city in the South, and push back U.S. Marines and South Vietnamese troops (Army of the Republic of Vietnam, or ARVN). The Marines and ARVN regroup and clear the city of the Viet Cong and PAVN. Around 5,000 civilians plus 500 ARVN and 250 U.S. troops are killed.
March 16, 1968 The Mai Lai Massacre takes place in a hamlet in South Vietnam. American soldiers kill approximately 500 South Vietnamese civilians—women, children, and elderly men. The soldiers encounter no resistance from the villagers nor do they find any evidence they were affiliated with the Viet Cong. A full-scale investigation occurs, and a few years later a lieutenant of the division is tried and found guilty of war crimes. The trial raises more questions about the war and U.S. involvement in South Vietnam.
March 31, 1968 President Lyndon B. Johnson announces the cessation of the bombing of the North, and the North's willingness to begin negotiations. He also announces he will not seek reelection. The war in Vietnam becomes a major issue in the 1968 Democratic presidential primaries.
May 10–20, 1969 The U.S. Army and their Vietnamese allies fight the PAVN in the Battle of Hamburger Hill. Repeated attempts are made to take control of Hill 937 occupied by the PAVN but the operation is unsuccessful. Public opinion turns against the the Vietnam War when Life magazine publishes photos of 242 American soldiers killed in a single week.
April 30, 1975 The Viet Cong and PAVN capture Saigon, the South Vietnamese capital. All American civilians and military personnel evacuate the city in an event that marks the end of the Vietnam War.

U.S. Troop Casualties in the Vietnam War, 1956-75

U.S. casualties in Vietnam were at their highest in 1968 but dropped significantly with the withdrawal of its land troops, beginning in June 1969.