The siege on Khe Sanh began on January 21, 1968 (ten days before the Tet Offensive), when 20,000 North Vietnamese troops, after many months of logistical buildup and moving heavy artillery into the heights surrounding Khe Sanh, began a barrage of artillery, mortar, and rocket fire into the Khe Sanh combat base, which was defended by 6,000 U.S. Marines and some elite South Vietnamese troops. Another 20,000 North Vietnamese troops served as reinforcements and also cut off road access to Khe Sanh, sealing off, and thus surrounding, the base. The 77-day battle featured 1. artillery duels by both sides; 2. Khe Sanh being supplied solely by air; 3. North Vietnamese probing attacks on the Khe Sanh base; and 4. North Vietnamese assaults to dislodge U.S. Marines outposts situated on a number of nearby strategic hills.
(Taken from Vietnam War – Wars of the 20th Century – Twenty Wars in Asia – Vol. 5)
Khe Sanh While the Tet Offensive was ongoing, General Westmoreland continued to believe that the Tet Offensive was a diversion for a major North Vietnamese attack in the north, particularly on the Khe Sanh American combat base, in preparation for a full invasion of South Vietnam’s northern provinces. Thus, he sent back only few combat troops already committed to defend the towns and cities. After the war, North Vietnamese officials have since insisted that the Tet Offensive was their main objective, and that their attack on Khe Sanh was merely a diversion to draw away U.S. forces from the Tet Offensive. Some historians also postulate that North Vietnam planned no diversion at all, but that its purpose was to launch both the Khe Sanh and Tet offensives.
Based on the second scenario, North Vietnam planned the siege at Khe Sanh as a repetition of its successful 1954 siege of the French base at Dien Bien Phu. A North Vietnamese victory at Khe Sanh would have the Americans meet the same fate as the French at Dien Bien Phu. Conversely, the U.S. military wanted Khe Sanh to be a major showdown with the North Vietnamese Army, where overwhelming American firepower would be brought to bear in battle and inflict serious losses on the enemy.
The siege on Khe Sanh began on January 21, 1968 (ten days before the Tet Offensive), when 20,000 North Vietnamese troops, after many months of logistical buildup and moving heavy artillery into the heights surrounding Khe Sanh, began a barrage of artillery, mortar, and rocket fire into the Khe Sanh combat base, which was defended by 6,000 U.S. Marines and some elite South Vietnamese troops. Another 20,000 North Vietnamese troops served as reinforcements and also cut off road access to Khe Sanh, sealing off, and thus surrounding, the base. The 77-day battle featured 1. artillery duels by both sides; 2. Khe Sanh being supplied solely by air; 3. North Vietnamese probing attacks on the Khe Sanh base; and 4. North Vietnamese assaults to dislodge U.S. Marines outposts situated on a number of nearby strategic hills.
In early April 1968, the Siege of Khe Sanh ended, with U.S. air firepower being the decisive factor. By then, American B-52 bombers had dropped some 100,000 tons of bombs (equivalent to five Hiroshima-size atomic bombs), which wreaked havoc on North Vietnamese positions. U.S. bombing also destroyed the extensive network of trenches which the North Vietnamese were building to inch ever closer to U.S. positions. The North Vietnamese planned to use the trenches as a springboard for their final assault on Khe Sanh. (The Viet Minh had used this tactic to overrun the Dien Bien Phu base in 1954.) North Vietnamese forces retreated to Laos and North Vietnam. Combat fatalities during the siege of Khe Sanh included 270 Americans, 200 South Vietnamese, and 10,000 North Vietnamese soldiers.