In 1967 North Vietnamese forces began building up around the Khe Sanh air base. NVA soldiers would continue to be spotted in the area but no attack would come. Commanders were faced with the decision to either reinforce the base or abandon it. They elected to reinforce it, setting up one of the longest battles of the war.
In January, US forces learned that an attack would soon come and on January 21st of 1968 it would begin. One of the surrounding hill outposts was attacked and the base at Khe Sanh received heavy shelling. The initial attack was thwarted but the NVA did manage to breach the Marine defenses at one point.
Fighting at Khe Sanh would continue for over two months with NVA troops assaulting nearby outposts and constantly shelling the base.
During the siege of Khe Sanh resupplying the air base would prove difficult. Land resupplies would prove impossible so the only option was air drops. Because of the heavy anti aircraft fire in the area, this was not going to be an easy task. Cargo plains would have to brave heavy fire during resupplies and develop special tactics to make it in and out safely.
Airpower would prove to be the lifeline for the base. They depended on it for supplies and the firepower was much needed to pound the surrounding area and suppress the enemy. Without the superiority of US airpower, the base would have surely been overrun.
The siege of Khe Sanh would continue through March, 77 days in all. In March, NVA troops began exiting the area, although shelling of the base would continue. US troops were eventually able to break through the remaining attacking forces and put an end to the battle.
From a numbers standpoint, the offensive was a huge loss for the NVA. Americans suffered casualties of 703 killed and 2642 wounded. NVA losses, are estimated to be greater than 10,000 dead.
Psychologically, the siege had an effect though. It proved what the enemy was willing to, they were willing to incur massive losses. This fact alone would raise questions about how long this war would really take to win.