America's Foreign Policy Practice Exam 2025 - Free Practice Questions and Study Guide

The Gulf of Tonkin incident in 1964 significantly escalated U.S. military involvement in Vietnam. This event involved two reported attacks on U.S. naval vessels by North Vietnamese forces in the Gulf of Tonkin. The first attack occurred on August 2, 1964, and the second, more controversial attack, was reported on August 4, although the details of this latter incident have been disputed and later viewed with skepticism.

In response to these events, Congress passed the Gulf of Tonkin Resolution, which effectively granted President Lyndon B. Johnson broad authority to use military force in Vietnam without an official declaration of war. This resolution marked a turning point, leading to a substantial increase in American military presence in Vietnam, the intensification of combat operations, and a commitment to engage more deeply in the conflict.

Other events listed, such as the Battle of Dien Bien Phu, were important in the context of Vietnam's history and U.S. involvement but were earlier in timeline and context. The Tet Offensive, which occurred in 1968, was a major turning point in public perception of the war but came after the Gulf of Tonkin incident. The signing of the Paris Peace Accords took place even later, in 1973,