About 16,000 U.S. soldiers from the 1st and 25th Infantry Divisions, 173rd Airborne Brigade and 11th Armored Cavalry Regiment join 14,000 South Vietnamese troops to mount Operation Cedar Falls.
This offensive, the largest of the war to date, was designed to disrupt insurgent operations near Saigon, and had as its primary targets the Thanh Dien Forest Preserve and the Iron Triangle, a 60-square-mile area of jungle believed to contain communist base camps and supply dumps. During the course of the operations, U.S. infantrymen discovered and destroyed a massive tunnel complex in the Iron Triangle, apparently a headquarters for guerrilla raids and terrorist attacks on Saigon. The operation ended with 711 of the enemy reported killed and 488 captured. Allied losses were 83 killed and 345 wounded. The operation lasted for 18 days.