Their goal in Laos seemingly achieved, President Thieu and General Lãm ordered a withdrawal of ARVN forces beginning on 9 March that was to continue through the rest of the month, destroying Base Area 604 and any supplies discovered in their path.
General Abrams implored Thieu to reinforce the troops in Laos and that they keep disrupting the area until the beginning of the rainy season.
By the time this request was made, South Vietnam possessed only one Marine brigade in its entire national reserve.
Thieu responded to Abrams by requesting that U.S. forces be deployed to Laos, knowing that such an option was impossible.
 The battle was shifting to Hanoi's advantage.
Anti-aircraft fire remained devastating and the PAVN had no trouble resupplying or reinforcing their troops in the battle area.
As soon as it became evident that ARVN forces had begun a withdrawal, the PAVN increased its efforts to destroy them before they could reach South Vietnam.
Anti-aircraft fire was increased to halt or slow helicopter resupply or evacuation efforts, the undermanned firebases were attacked, and ARVN ground forces had to run a gauntlet of ambushes along Route 9.

Only a well-disciplined and coordinated army could have executed an orderly withdrawal in the face of such a determined enemy and the South Vietnamese force in Laos was neither.
The retreat quickly devolved into a rout.
One by one, the isolated firebases were closed out or overrun by the PAVN and each withdrawal was costly.
On 21 March, South Vietnamese Marines at FSB Delta (16.550°N 106.539°E), south of Route 9, came under intense ground and artillery attacks.
During an attempted extraction of the force, seven helicopters were shot down and another 50 were damaged, ending the evacuation attempt.
The Marines finally broke out of the encirclement and marched to the safety of FSB Hotel, which was then hastily abandoned.
During the extraction of the 2nd ARVN Regiment, 28 of the 40 helicopters participating were damaged.

The armored task force fared little better, losing many of its vehicles to  breakdowns or ambushes.
During the retreat, the task force lost 60 percent of its tanks and half of its APCs.
It also abandoned 54 105mm and 28 155mm howitzers.
This equipment then had to be destroyed by U.S. aircraft in order to prevent its capture and reuse by the PAVN.
Covering the retreat on Route 9 was the 1st Armored Brigade, which had been assigned to the ARVN Airborne Division.
When informed by a prisoner that two PAVN regiments waited in ambush ahead, the commander of the brigade, Colonel Nguyen Trong Luat, notified General Đống of the situation.
The Airborne commander airmobiled forces in and cleared the road, but never bothered to inform Colonel Luat.
In order to avoid destruction on Route 9, Luat then ordered the column to abandon the road only 5 miles (8.0 km) from the South Vietnamese border and plunged onto a jungle trail looking for an unguarded way back.

The trail came to a dead end at the steep banks of the Se Pone River and the force was trapped.
The PAVN closed in and savage rearguard actions ensued.
Two bulldozers were finally helilifted into the ARVN perimeter to create a ford, and the survivors of the force crossed into South Vietnam on 23 March.
On the night of 23 March, a PAVN sapper attack on Khe Sanh resulted in 3 Americans killed and several aircraft and 2 ammunition dumps destroyed, PAVN losses were 14 killed and 1 captured.
By the 25th, 45 days after the beginning of the operation, the remainder of the South Vietnamese force that had survived had left Laos.
The forward base at Khe Sanh had also come under increasing artillery bombardment and, by 6 April, it was abandoned and Operation Lam Son 719 was over.
Their goal in Laos seemingly achieved, President Thieu and General Lãm ordered a withdrawal of ARVN forces beginning on 9 March that was to continue through the rest of the month, destroying Base Area 604 and any supplies discovered in their path. General Abrams implored Thieu to reinforce the troops in Laos and that they keep disrupting the area until the beginning of the rainy season. By the time this request was made, South Vietnam possessed only one Marine brigade in its entire national reserve. Thieu responded to Abrams by requesting that U.S. forces be deployed to Laos, knowing that such an option was impossible.  The battle was shifting to Hanoi's advantage. Anti-aircraft fire remained devastating and the PAVN had no trouble resupplying or reinforcing their troops in the battle area. As soon as it became evident that ARVN forces had begun a withdrawal, the PAVN increased its efforts to destroy them before they could reach South Vietnam. Anti-aircraft fire was increased to halt or slow helicopter resupply or evacuation efforts, the undermanned firebases were attacked, and ARVN ground forces had to run a gauntlet of ambushes along Route 9.
Only a well-disciplined and coordinated army could have executed an orderly withdrawal in the face of such a determined enemy and the South Vietnamese force in Laos was neither. The retreat quickly devolved into a rout. One by one, the isolated firebases were closed out or overrun by the PAVN and each withdrawal was costly. On 21 March, South Vietnamese Marines at FSB Delta (16.550°N 106.539°E), south of Route 9, came under intense ground and artillery attacks. During an attempted extraction of the force, seven helicopters were shot down and another 50 were damaged, ending the evacuation attempt. The Marines finally broke out of the encirclement and marched to the safety of FSB Hotel, which was then hastily abandoned. During the extraction of the 2nd ARVN Regiment, 28 of the 40 helicopters participating were damaged.
The armored task force fared little better, losing many of its vehicles to  breakdowns or ambushes. During the retreat, the task force lost 60 percent of its tanks and half of its APCs. It also abandoned 54 105mm and 28 155mm howitzers. This equipment then had to be destroyed by U.S. aircraft in order to prevent its capture and reuse by the PAVN. Covering the retreat on Route 9 was the 1st Armored Brigade, which had been assigned to the ARVN Airborne Division. When informed by a prisoner that two PAVN regiments waited in ambush ahead, the commander of the brigade, Colonel Nguyen Trong Luat, notified General Đống of the situation. The Airborne commander airmobiled forces in and cleared the road, but never bothered to inform Colonel Luat. In order to avoid destruction on Route 9, Luat then ordered the column to abandon the road only 5 miles (8.0 km) from the South Vietnamese border and plunged onto a jungle trail looking for an unguarded way back.
The trail came to a dead end at the steep banks of the Se Pone River and the force was trapped. The PAVN closed in and savage rearguard actions ensued. Two bulldozers were finally helilifted into the ARVN perimeter to create a ford, and the survivors of the force crossed into South Vietnam on 23 March. On the night of 23 March, a PAVN sapper attack on Khe Sanh resulted in 3 Americans killed and several aircraft and 2 ammunition dumps destroyed, PAVN losses were 14 killed and 1 captured. By the 25th, 45 days after the beginning of the operation, the remainder of the South Vietnamese force that had survived had left Laos. The forward base at Khe Sanh had also come under increasing artillery bombardment and, by 6 April, it was abandoned and Operation Lam Son 719 was over.
Operation Lam Son 719