U.S. Army Bell AH-1G HueyCobra attack helicopters over Laos.
This operation was executed by US and South Vietnamese forces against the growingly confident and ingenious forces of the north under the cautious and cunning Giap. The fact that some have considered it a failure does not make it any less instructive with regard to the problems of conducting the air-land battle and the merging of new technology (helicopters) with the clogging terrain and timeless verities of war. The sweating mountain forests on the Vietnam-Laos border imposed a unique character on operations, like any distinctive terrain. General Dave Palmer described the area on the Vietnam-Laos border as a `forbidding verdant fastness over which the communists had wisely and energetically superimposed a superb, in depth defensive system’. The aim of the operation was to destroy the North Vietnamese base area in Laos, especially the numerous logistic installations around Muang Xepon (Tchepone), thus forestalling any North Vietnamese offensive to conquer the northern provinces of the Republic of Vietnam. It was a spoiling attack in four phases: first, US forces would seize the approaches inside South Vietnam leading to the Laotian border. Then, the 1st South Vietnamese Corps would attack along highway 9 to Xepon in a series of leap-frogging air assaults and armoured advances. Third, the South Vietnamese forces would carry out search and destroy missions in area 604. Depending on opportunity, the fourth phase was either a withdrawal along highway 9 or further destructive missions in area 611. The operation was named after the defeat of the Chinese invasion in 1427. The operation has been described as one of mid-intensity war, perhaps in recognition of the heavy hand of political restraint which constantly impinged on all the Vietnam fighting. For the first time, South Vietnamese forces were employed on a large scale without American ground forces, who were forbidden to enter Laos, or even any American advisers. On the other hand, the Americans dominated the skies and flew thousands of missions in support. In terms of numbers engaged and casualties, this was undoubtedly an operation of major war, and is particularly interesting as an air-land battle.
The operation began at midnight on 30 January 1971, the Americans firing heavy artillery concentrations from positions inside Vietnam. Meanwhile, military engineers began to make bases abandoned after the 1968 Khe Sanh campaign fit to mount air sorties, and Khe Sanh itself, the American Verdun, was re-opened as a forward base. It was estimated that this would take four days: in fact, it took over a week longer because of weather, mines and unexploded shells. Meanwhile, the operation had to go on and the South Vietnamese ground forces moved into Laos on 8 February.
The shape of the land inevitably channels an approach to Xepon along the Ye Pon river valley. The valley was so narrow that there was hardly room for the leading three armoured squadrons to manoeuvre. Meanwhile, cloud swathed the high ground on either side of the valley, naturally funnelled helicopters into it, and the silver gleam of the river was the most obvious navigation landmark. The North Vietnamese knew this well, and the nineteen anti-aircraft artillery battalions in the area were sited with this in mind, and also around the few obvious helicopter landing sites, which were self-evident amidst the dizzy vista of jungle and mountain. Artillery fire on all likely helicopter landing zones was pre-planned. As a result the Americans came up against much stiffer fire from the ground than they had expected, and helicopter gunships had to be allocated to escort even casualty evacuation helicopters in order to suppress ground fire, reducing their availability for other tasks. When the South Vietnamese forces landed, they were savagely counter-attacked, and one landing zone, 31, was overrun by North Vietnamese T-34 tanks which, seldom having faced heavy ordnance on the other side before, the air-landed forces were ill-equipped to counter. The American Army Aviation commander for the operation concluded that more emphasis needed to be placed on the anti-tank helicopter.
After several weeks of limited success, the South Vietnamese commander abandoned plans for a straight ground advance west of Aloui, and instead set up helicopter bases for an air assault towards Xepon. On 6 March two battalions carried out a desant (a Russian term which summarizes the type of manoeuvre graphically) into landing zone Hope, and in spite of enemy anti-air defences lost only one helicopter out of 120 employed. This and other air assaults were carefully planned, co-ordinating various layers of air elements: strategic bombers raining bombs from miles high, tactical bombers swathing anti-aircraft positions with fire, and helicopters and air-delivered smokescreens to guard the air-mobile infantry as they actually landed.
Meanwhile, general Giap threw everything he could into an attempt to destroy the raiding force: 36,000 North Vietnamese troops including two armoured regiments with T-34 tanks attacked the penetration. In order to escape American bombing, the North Vietnamese hugged the South Vietnamese positions, accepting terrible casualties from their ground fire instead: it is estimated that 10,000 to 15,000 were killed. The ARVN forces accomplished their mission, destroying the support facilities around Xepon before withdrawing. They thus delayed a major North Vietnamese offensive for a year, but two crack divisions, the 1st Division and the Airborne Division, had been terribly mauled in the process. Expert opinion is therefore sharply divided on the success of the operation: one authority considered that the South Vietnamese forces were `routed’: another that they broadly succeeded in their missions and had a major effect in delaying further North Vietnamese advances.
No US troops were involved on the ground, but the Americans provided lavish air support for Lam Son 719. They flew 160,000 air sorties, losing 107 helicopters to enemy fire. There were over 10,000 strikes by tactical fixed-wing aircraft, and the B-52 heavy bombers dropped 46,000 tons of bombs.
Many observers have cited Lam Son 719 as proof that air-mobile operations are too vulnerable to enemy air defence and counter-attack on the ground and could not be carried out in mechanized wars. Yet the loss of 107 helicopters, although high, must be seen in context. Out of 160,000 sorties over nearly two months (the last South Vietnamese troops fell back over the border on 24 March), that is not unacceptable, bearing in mind that war is a horribly expensive, bloody business. The terrain neutralized many of the advantages of the air-mobile force, allowing the defenders to concentrate on known axes of advance. This and low cloud over the land forced the helicopters up, flying at perhaps 1000 metres and more. It is ironic that although in some ways helicopters free military activity from the constraints of terrain, in others they are more dependent on it. Lam Son 719 did not prove conclusively that air-mobile operations are impossible. The operation has many lessons for future war, especially as the North Vietnamese were well provided with organic air defences and artillery, and both the Americans and Russians have studied it in developing their own doctrine for employing the air elements of ground forces. It was the first great air-land battle using helicopters in major war.