An Cosantóir

www.military.ie the defence forces magazine | 27 At 0500hrs the main base in Khe Sanh was targeted by an intense artillery, rocket and mortar barrage. One shell detonated the base's arms dump and 1,500 tonnes of ordnance were destroyed, reducing the supply of heavy artillery shells for the base's guns from 11,000 down to 4,000, leaving the gunners no option other than to reduce their rate of fire to ration their ammunition. At first US forces could not iden- tify the NVA's artillery positions (152mm howitzers with a range of up to 17km), which were dug into granite caves across the border in Laos, giving them a huge tactical and operational advantage. However, using crater analysis to determine the direction and angle of incoming rounds, the Marines were eventually able to locate the NVA gun posi- tions and call in an air strike by B52 Stratofortresses, dropping 30 tonnes of ordnance per plane. Though many NVA soldiers were killed, the attacks failed to destroy the gun positions as they were so well dug in. By 6th February the siege was into its seventeenth day. Daily artillery duels and probing attacks by the NVA had resulted in little ground being taken, and the NVA turned their attention to the US outpost at Lang Vei, 7km from the main base and the only obstacle hindering an all-out attack on Khe Sanh from the west. Guarding this outer post were 400 local troops from the South Vietnamese Army (ARVN) and 24 US Marines. Assaults against the position were fierce, with the Marines forced to go on the defensive; tactics they were not used to. Soviet-built PT76 tanks supported by NVA infantry overran the camp in a matter of min- utes, although the Marines and their allies fought on for several hours, destroying many of the tanks using LAW, single-shot, anti-tank rockets. Making a last stand at their tactical ops centre, the soldiers called in an artillery strike on their own position, forcing the NVA to fall back. While a rescue mission from Khe Sanh managed to ex- tract the few survivors out of the battle zone and return to base, the fall of the position left the way clear for an all-out attack on Khe Sanh. By 25th February a major assault on the US base was imminent. A recon patrol that ventured out was engaged 400m outside the wire and suffered heavy casualties. Soon, wave after wave of NVA infantry were assault- ing the main base only to be repulsed by grenades and small-arms fire. Repeated calls for reinforcements were refused as the bulk of US forces in the country were bus- ily engaged defending against a nationwide attack that was to become known as the Tet Offensive. There was to be no ground support for the Marines under siege at Khe Sanh. To break the NVA stranglehold on the base the defenders would have to rely on the air power provided by Operation Niagara, which had been established to proved close air support, and which saw tactical fighter- bombers and B52s, operating at altitudes of 35,000ft, dropping around 40,000 tonnes of bombs, some to within 600 yards of the Khe Sanh base. With the massive destructive power of the B52s the tide of the battle turned. For two months the NVA had been the aggressors but the devastating effect of relent- less air strikes, coupled with their inability to overrun Khe Sanh, were forcing the NVA to begin the withdrawal of its forces. On March 30th, the Khe Sanh Marines counter- attacked the NVA, forcing them to withdraw further. A relief force, code-named 'Pegasus', was launched, with army and Marine forces securing Route 9, the only road into Khe Sanh from the east. By April, the base had been reinforced, bringing to an end the bloody siege of Khe Sanh. Many US commanders consider the Battle of Khe Sanh to be the greatest victory of the war. Casualty figures numbered 897 Allied soldiers killed, with 2,000 injured, while the NVA estimated that ¼ of its force of 40,000 soldiers had been killed in action. The US conducted a tactical withdrawal from the Khe Sanh combat base in July 1968. General Võ Nguyên Giáp General William Westmoreland

• Cover