What led to the Gulf of Tonkin incident in Vietnam?

What led to the Gulf of Tonkin incident in Vietnam?

Overview of the Gulf of Tonkin incident, which led to the United States becoming directly involved in the Vietnam War.
Encyclopædia Britannica, Inc.
  • Encyclopædia Britannica, Inc.
    Learn more about the consequences of the Korean War.
  • Encyclopædia Britannica, Inc.
    Women weren't passive observers to the war around them.
    Media Editor: Lauren Sims
  • StringersHub/Reuters
    Bystander video footage taken during the protests in Iran in January 2026 shows Iranian security forces running as they are chased by protesters. 
    Media Editor: Meg Matthias
  • Encyclopædia Britannica, Inc.
    Scenes from the 1960 Democratic Party primary election campaigns, with U.S. Sen. John F. Kennedy striving to prove himself to the public and to party leaders in the race to become the Democratic nominee in the U.S. presidential election.
  • Encyclopædia Britannica, Inc.
    In August 1964, in response to an alleged attack by North Vietnamese patrol boats on U.S. destroyers in the Gulf of Tonkin, the U.S. Congress authorized Pres. Lyndon B. Johnson to take any action necessary to deal with threats against U.S. forces and allies in Southeast Asia. From Vietnam Perspective (1985), a documentary by Encyclopædia Britannica Educational Corporation.
  • Encyclopædia Britannica, Inc.
    The Tet Offensive was a military failure for the Viet Cong, but, at the same time, it devastated the American public's support for the war. From Vietnam Perspective (1985), a documentary by Encyclopædia Britannica Educational Corporation.
  • Encyclopædia Britannica, Inc.
    Decades later, the Civil Rights Act is still a critical piece of American legislation.

Transcript

The Gulf of Tonkin incident was a naval event off the coast of Vietnam that ultimately gave President Lyndon B. Johnson the power to greatly escalate the U.S. military’s direct involvement in Vietnam in 1964. Encyclopaedia Britannica presents some key points on the Gulf of Tonkin Incident.

Vietnam was divided into two halves, north and south. U.S. naval vessels were sent to the Gulf of Tonkin in support of South Vietnam to observe and intercept communications from communist North Vietnam. In late July 1964, South Vietnamese commandos attacked North Vietnamese military installations on the islands of Hon Me and Hon Ngu in the Gulf of Tonkin.

The destroyer USS Maddox saw North Vietnamese torpedo boats sent out in pursuit of the South Vietnamese vessels, and it retreated, but it returned to the area on August 1. The following day, the Maddox was approached by three North Vietnamese torpedo boats. The Maddox fired warning shots, but the torpedo boats continued to follow and proceeded to open fire.

The Americans believed that North Vietnam had targeted the Maddox unprovoked, so the destroyer USS Turner Joy was sent in as reinforcement. Unbeknownst to those aboard the Maddox, the North Vietnamese believed that the Maddox had been involved in the South Vietnamese attacks on Hon Me and Hon Ngu.

The U.S. military intercepted communications on August 4 that led them to believe North Vietnam was planning to attack the Maddox and Turner Joy. That night, with a storm raging, both ships reported that they were being approached by unidentified vessels and requested air support. The plane piloted by James Stockdale came to assist the destroyers but saw no torpedo boats.

After the event, Captain John Herrick of the Maddox sent a message: “Review of action makes many reported contacts and torpedoes fired appear doubtful. Freak weather effects on radar and overeager sonarmen may have accounted for many reports. …Suggest complete evaluation before any further action taken.” Despite the uncertainty, President Johnson informed the United States Congress that the two naval destroyers had been attacked by the North Vietnamese.

This prompted Congress to pass the Gulf of Tonkin Resolution, which gave the president the right to take all necessary measures to repel any armed attack against the United States. This resolution and the Gulf of Tonkin incident resulted in the U.S. getting directly involved in Vietnam. The resolution was later repealed, as many members of Congress believed that it gave the president a blanket power to wage war.