During the 1960s, the United States kept a close eye on Southeast Asia in the hope that it would not succumb to Communism like a line of falling dominos. Tension between the United States and North Vietnam the main communist threat in former Indochina came to a head on August 2, 1964, when three North Vietnamese torpedo boats engaged the USS Maddox in the Gulf of Tonkin. The resulting maritime clash led to four Vietnamese deaths and moderate to severe damage to its sea crafts; the U.S. emerged virtually unscathed, with no casualties and minimal vessel damage.
The Gulf of Tonkin Incident refers to two clashes on August 2 and August 4, 1964, but a National Security Agency document declassified in 2005 later revealed that the second attack did not actually occur. Conflict or not, the event resulted in U.S. Congress passing the Tonkin Gulf Resolution, which allowed then President Lyndon B. Johnson to intervene in the face of "communist aggression" and escalate U.S. involvement in Vietnam.