Operation Lam Son 719, 1971: South Vietnam's drive into Laos

Lam Son 719 was meant to show that South Vietnam's army could fight on its own while American troops went home. It turned into some of the heaviest fighting of the war, and the pictures of South Vietnamese soldiers clinging to the skids of helicopters leaving Laos became one of its most lasting images.²

Background: cutting the trail

The Ho Chi Minh Trail, a web of roads and tracks through eastern Laos, carried North Vietnam's men and supplies south. Its hub in the Laotian panhandle was Base Area 604, around the small town of Tchepone, where the supply routes met. After the incursion into Cambodia in 1970 cut other routes, North Vietnam shifted more of its logistic effort to this Laotian corridor.³ › Operation Menu, 1969

The allied leaders now turned to the Laotian border. At the urging of President Nixon's staff, General Creighton Abrams, the American commander in Vietnam, worked out with the South Vietnamese Joint General Staff a drive along Route 9 to Tchepone, to wreck the supply bases there and forestall a North Vietnamese offensive.⁴

It was also a political test. Under the Cooper-Church Amendment, passed by Congress in late 1970, no American ground troops or advisers could enter Laos. For the first time South Vietnamese units would go into battle without their American advisers, a test of President Nixon's Vietnamization, the policy of handing the war to the South Vietnamese.⁵

Armies and commanders

The attack was led by Lieutenant General Hoang Xuan Lam, commander of the South Vietnamese I Corps, with the Airborne Division, the 1st Infantry Division, the Marine Division, the 1st Armored Brigade and a group of Ranger battalions. At its peak about 17,000 South Vietnamese troops were in Laos; 34 battalions fought there. On the American side Lieutenant General James W. Sutherland's XXIV Corps supplied artillery from inside South Vietnam, logistics and the helicopters on which everything depended.⁶

Allied intelligence underestimated the enemy. Willbanks cites pre-operation estimates of about 11,000 North Vietnamese in the area, half of them support troops; the Army's intelligence historian Erin Thompson gives an estimated 22,000 around Tchepone. Both note that reinforcements could arrive faster than planners assumed. In the end North Vietnam committed 12 infantry regiments from five divisions, with tank and artillery regiments: more than 60,000 men by Willbanks's count, and about 30,000 combat troops plus 10,000 to 20,000 in the trail's logistic units by Hinh's.⁷

The battle in phases

Dewey Canyon II and the crossing

In the first phase, Dewey Canyon II, American troops of the 1st Brigade, 5th Infantry Division, cleared Route 9 up to the border and reopened the old base at Khe Sanh, while engineers repaired its airstrip. Bad weather cancelled many of the air strikes meant to destroy North Vietnamese anti-aircraft guns before the attack.⁸

On 8 February the South Vietnamese crossed the border. An armored column drove west along Route 9, a single-lane dirt road, while Rangers and paratroopers were landed on hills to the north and the 1st Division on the escarpment to the south, where they built fire support bases. By 10 February the column had taken A Luoi and Ban Dong, with large caches of weapons, fuel and food.⁹

The halt

Then, on 11 February, the advance stopped a few kilometers beyond A Luoi. Thieu had told Lam to move carefully and avoid heavy casualties, which could hurt him in the elections due that fall. When Lam reported on 19 February that the enemy was growing stronger, Thieu told him to take his time and search toward the southwest instead. The pause gave the North Vietnamese time to bring in reinforcements and surround the stalled column.¹⁰

The firebases fall

The North Vietnamese answered by ringing the hilltop bases with anti-aircraft guns, shelling them day and night, and then assaulting them. Ranger Base North was surrounded and fell on 20 February; its survivors fought their way out to Ranger South, leaving 178 men dead or missing. In the course of the operation some panicked soldiers clung to the skids of evacuation helicopters, and the pictures came to stand for the whole operation, although, as Willbanks stresses, most of the Rangers fought hard.¹¹

On 25 February North Vietnamese infantry and an estimated 20 tanks overran Fire Support Base 31, held by the 3rd Airborne Brigade; the brigade commander was captured. An armored relief force fought three battles on its way north between 25 February and 1 March, but never reached the base. Fire Support Base 30 had to be abandoned on 3 March after its guns had all been damaged.¹²

Why the relief never got through is still argued. Willbanks reports that the airborne division's senior American adviser blamed the armor commander for ignoring orders, while the adviser to the armored brigade said it had received conflicting orders from Lam and from the airborne division's commander. Hinh, for his part, blames the Airborne Division's lack of contingency planning and an armor commander who was not resourceful enough for a fight against tanks deep in the jungle.¹³

For the American helicopter crews every flight into Laos was a run through heavy anti-aircraft fire. Thompson writes that the poor weather and the failure to destroy the enemy's anti-aircraft guns cost the allies dearly in men and machines.¹⁴

Turning point: Tchepone

With the operation stalled, Thieu shifted its aim from destroying supply bases to simply taking Tchepone. Willbanks calls it a public relations move ahead of the elections. Hinh, who commanded a South Vietnamese division himself, judges the result a symbolic gesture rather than a real achievement: it merely meant that "we were there." The real prize, he adds, the enemy's supply caches, lay further west, out of reach.¹⁵

From 3 to 6 March, in one of the largest airmobile operations of the war, American helicopters landed troops of the 1st Division on a chain of landing zones along the escarpment south of Route 9, named Lolo, Liz, Sophia and Hope. The landing at Lolo alone cost 11 helicopters shot down and 44 damaged. On 6 March some 120 Hueys flew two battalions from Khe Sanh to Hope, four kilometers northeast of Tchepone, and on 7 March the troops entered the ruined town.¹⁶

The retreat

It was the last good news. With Tchepone taken and his best units in danger, Thieu ordered the withdrawal. Over the following weeks the South Vietnamese fought their way back toward the border under heavy pressure from North Vietnamese tanks, infantry and artillery. Route 9 became a tangle of abandoned and destroyed vehicles; in all the South Vietnamese lost 54 tanks and 96 artillery pieces. A U.S. Army historian has the last of them out of Laos by 23 March; Willbanks and Hinh both note that almost all had left by 25 March.¹⁷

Aftermath

The losses were heavy, and the figures differ. Saigon officially admitted about 1,150 killed, some 4,200 to 4,300 wounded and 240 to 250 missing; the press put them at about 3,800 killed, 5,200 wounded and 775 missing. The U.S. XXIV Corps counted 7,683 South Vietnamese casualties, killed, wounded and missing. American losses in Lam Son 719 and Dewey Canyon II came to 1,402: 253 killed or missing and 1,149 wounded.¹⁸

The helicopter crews paid a high price. Willbanks counts 107 helicopters destroyed and 601 damaged; Hinh's table of Army aircraft gives 108 destroyed, 82 of them in Laos, and 618 damaged. North Vietnamese losses were also severe. Allied reports claimed about 19,000 to 19,400 enemy killed, while by Thompson's account Hanoi admitted some 10,000 casualties; Hinh and Willbanks both estimate that North Vietnam lost up to half the troops it committed.¹⁹

Thieu declared the operation a success. Thompson and Hinh both write that by forcing North Vietnam to spend so many men and supplies, it forestalled an offensive in 1971; Hanoi's next great blow came in the spring of 1972. But the retreat hit South Vietnamese morale hard, and Willbanks writes that the troops who came back from Laos believed they had been beaten.²⁰ › The Battle of Khe Sanh, 1968

Legacy and memory

Lam Son 719 became the measure of Vietnamization, and the verdicts are harsh. General Bruce Palmer Jr., quoted by Thompson, called it at best a shaky draw and in reality a psychological defeat for the South Vietnamese army. Willbanks judges the outcome mixed: real damage to the North Vietnamese and their supply system, but proof that Vietnamization was still a work in progress. Hinh, writing as one of the South Vietnamese commanders, recalls the grave concern that the pictures of battered troops coming back across the border caused at home.²¹

The operation also exposed how much the South Vietnamese army still depended on American air power, helicopters and logistics, and how far political caution reached into its command. Little more than a year later, in the spring of 1972, North Vietnam struck again with a far larger offensive.²² › The fall of Saigon, 1975