on november 1, just after midnight, a viet cong mortar company rode sampans down a river that led to the Bien Hoa air base, home to some of the most sophisticated U. S. aircraft in South Vietnam. On orders from General William Westmoreland, a South Vietnamese Airborne battalion was guarding the base, but the mortar company managed to evade the paratroopers' patrols. One and a half miles from the airfield, the guerrillas brought the sampans ashore and set up their 81mm mortars in a meadow of shoulder-high brush. Over the next thirty-nine minutes, they lobbed 100 rounds at the airfield and hit an important target with almost every round, a sure indication that Viet Cong spies had infiltrated the base beforehand and paced off the range to the targets. The shells shattered the airfield's control tower and an American barracks, killing four Americans and wounding thirty. Aircraft casualties totaled twenty-seven, including eleven B-57 bombers worth 1.25 million dollars apiece.

Ambassador Taylor, General Westmoreland, and Admiral Sharp demanded immediate retaliation, to show the enemy that such attacks would not be tolerated and to inspire the South Vietnamese government. The Joint Chiefs of Staff called for both heavy air strikes in North Vietnam and Laos and the introduction of Marine units into South Vietnam to protect American installations. So important did the Joint Chiefs consider the matter that they warned the President, through Secretary of Defense McNamara, that if he refused to respond militarily, then the United States should get out of Vietnam.