The Free World Counteroffensive

Opening Operations

At 0600, 30 March, U.S. Army, Marine, and Vietnamese Army forces initiated their planned deception operation northeast of Dong Ha. The U.S. element consisted of the 3d Squadron, 5th Cavalry; Company C, 2d Battalion, 34th Armor; Company A, 1st Battalion, 502d Airborne, 101st Airborne Division; and 2d Battalion, 4th Marine Regiment; all controlled by the 3d Marine Division. The Vietnamese Army element consisted of the 1st Battalion, 2d Infantry, and the 3d Battalion, 1st Infantry, under the control of the 1st Vietnamese Army Infantry Division. The maneuver elements attacked generally north toward the demilitarized zone along the coastal plains near Gio Linh. All units reached their objectives that afternoon. Following only light action, the operation was terminated on the afternoon of 1 May.

The broad concept for the relief of Khe Sanh envisioned the 1st Cavalry Division attacking west from Ca Lu to seize the high ground along Highway 9 in a series of successive air mobile assaults. Concurrently the marines were to secure and repair Highway 9 leading to Khe Sanh. Under the single manager concept for air, intensive close air support was to assist the attacks, together with massive B-52 strikes prior to and during the assault. Major units reinforcing the 1st Cavalry Division were the 1st Marine Regiment with three battalions and an airborne task force of three battalions, plus the supporting combat and service units. (Chart 3)

Operation PEGASUS began at 0700 on 1 April with U.S. Army, U.S. Marine, and Vietnamese forces moving out from Ca Lu along Highway 9 toward the Khe Sanh Combat Base. The 1st Cavalry Division attacked with a combination of air and ground assaults to clear and secure the road and remove the enemy from the area of operation. During the morning hours, the two lead Marine battalions moved out according to plan, pushing west from Ca Lu. Delayed by weather, it was not until 1300 that the initial waves of 1st Cavalry Division helicopters placed men of the 3d Brigade of the Cavalry on a series of landing zones as close as five miles to Khe Sanh. (Map 11)




Photo: THE 1ST CAVALRY DIVISION DISEMBARKS from UH-1B for a mission.

The 2d Battalion, 1st Marines, advanced westward on the north side of Route 9 while the 2d Battalion, 3d Marines, advanced on the south side of the road. As the Marines progressed and cleared Route 9 and the nearby terrain of enemy troops, engineer companies began repairing the road. They cleared one and a half kilometers of road and constructed four by-passes the first day. Throughout the operational area, the Americans spent a quiet night in rapidly prepared defensive positions.

Although Operation NIAGARA had been terminated with the beginning of PEGASUS, air support continued. The first day of the operation, eight B-52 raids were flown to assist the ground forces. Four of the missions were in the vicinity of Khe Sanh. Poor weather in the early daylight hours limited tactical fighter support to 66 sorties. Eight U.S. Air Force C-130 and four C-123 cargo aircraft delivered 115 tons the first day and 24 helicopter missions boosted the sum to just under 150 tons. An additional 44 personnel joined the combat base by way of C-123 aircraft, which were still permitted to land on the strip.

On 2 April operations began at 0655 with two Marine battalions resuming their advance along either side of Route 9 toward Khe Sanh. Contact with the enemy was minimal. The 2d Battalion, 7th Cavalry, began an air assault at 1300. The late starting time was


Map 11: Relief of Khe Sanh Operation Pegasus (Schematic No. 1)

MAP 11

attributed to ground fog, haze, and low hanging clouds. These unfavorable flying conditions continued throughout the operation.

The 1st Battalion, 1st Marines, remained near the air field north of Ca Lu, which had been designated Landing Zone STUD. The Marine unit retained this mission for the duration of the operation.

The Army, Navy, and Marine engineer units continued their work along Route 9. On 2 April they cleared almost three kilometers of the road and completed two bridges and two more bypasses. (Map 12)

The sustained air support included 36 B-52 aircraft delivering six strikes, five of which were in the immediate vicinity of Khe Sanh Combat Base. In spite of the unfavorable flying weather, 142 tactical air sorties were flown by Air Force, Navy, and Marine aircraft in support of the ground troops conducting PEGASUS. Air Force cargo aircraft dropped 91.4 tons of supplies into Khe Sanh and helicopters raised the total tonnage to 162.

On 3 April the tempo of the operation picked up somewhat. The marines continued westward along Route 9 with the engineers working furiously right on their heels. The 1st Cavalry's 3d Brigade continued operations in the vicinity of the landing zones they had occupied during the first day. The 2d Brigade of the 1st Cavalry


Division air-assaulted in the PEGASUS area of operations one day ahead of schedule with the 2d Battalion, 5th Cavalry, going into Landing Zone Tom and the 2d Battalion, 12th Cavalry, moving first to Landing Zone STUD by CH-47 helicopters, then reloading into smaller UH-1H helicopters for an air assault into Landing Zone WHARTON. The 1st Battalion, 5th Cavalry, then flew into Landing Zone WHARTON. Both landing zones received 'artillery and rocket fire from enemy positions during the moves, but the troops were not to be easily diverted. By the end of the day, all 2d Brigade troops and three batteries of the 1st Battalion, 77th Artillery, were in position. At that time, other artillery batteries in position included Battery C, 21st Artillery, which had followed the air assault troops into Landing Zone CATES, and B Battery, 21st Artillery, which had followed into Landing Zone MIKE on D-day. Battery A, 21st Artillery, joined the 2d Battalion, 7th Cavalry, at Landing Zone THOR on 2 April.

During the fourth day, April 4, the enemy resistance continued at a moderate level. The marines maintained their westward attack along the main supply route and the Third Brigade kept up pressure on enemy elements around the established landing zones. The 1st Battalion, 5th Cavalry, initiated an attack on an enemy battalion occupying positions in an old French fort.

On the same day, elements of the 26th Marine Regiment began their first major offensive move in weeks, attacking out of the Khe Sanh Combat Base. Preceded by extensive artillery preparation, at 0600 the 1st Battalion, 9th Marines, assaulted southeast towards their objective, Hill 471. The hill was secured by 1720 that day.

The fifth day, 5 April, opened with an enemy attack on Hill 471, which the Marines had occupied the previous afternoon. At 0515 the 7th Battalion, 66th Regiment, 304th North Vietnamese Division, charged up the hill. The fight was one of the highlights of Operation PEGASUS and was quite one-sided. Assisted by tremendous artillery and close air support, the marines cut down large numbers of the attackers while suffering few casualties themselves. (Map 13)

Elsewhere, except for the 1st Cavalry Division's 2d Brigade, the operation followed a routine pattern. The marines and the 2d Battalion, 7th Cavalry, maintained their westward movement, meeting moderate opposition along Route 9. The engineers had reconstructed a total of 5.5 kilometers of the road, completing four bridges and twelve by-passes.

The Marine advance along the main supply route continued through 6 April. The 2d Battalion, 7th Cavalry, maintained its drive west and met stubborn enemy resistance occasioning the heaviest fighting of the operation thus far. Following a day-long battle, the


Map 12: Relief of Khe Sanh Operation Pegasus (Schematic No.2)

MAP 12

cavalry finally drove the enemy out of his defensive positions, capturing 121 individual and 10 crew-served weapons.

The 2d Battalion, 12th Cavalry, was airlifted from Landing Zone TIMOTHY to Hill 471 and effected relief of the 1st Battalion, 9th Marines, at noon. The marines then opened a clearing attack to the northwest.

Meanwhile the 1st Battalion of the 5th Cavalry was encountering stiff resistance at an old French fort about 15 kilometers due east of Khe Sanh. On the sixth day of Operation PEGASUS the 1st of the 5th was extracted and the 2d Battalion of the 5th Cavalry picked up the mission of seizing the strongly defended position. The fort finally fell on 7 April thus eliminating the final known enemy strongpoint between the advance cavalry troopers and Khe Sanh.

Little further significant contact was to occur during the final days of the operation. The remainder of Operation PEGASUS was directed at opening the main supply route and sifting through the debris of battle. The retreating enemy continued to offer some resistance, but without spirit.

The seventh day, 7 April, witnessed a further lessening of enemy strength in the area of operations. Ground probes against friendly positions continued but fewer reports were made of attacks by enemy artillery.

At 0800 on 8 April, the relief of the Khe Sanh Combat Base was


Map 13: Relief of Khe Sanh Operation Pegasus (Schematic No.3)

MAP 13

accomplished as the 3d Brigade airlifted its command post into the base and assumed the mission of securing the position. The 2d Battalion, 7th Cavalry, cleared Route 9 to the base and linked up with the marines.

By this time it was apparent that the enemy had chosen to flee rather than face the highly mobile Americans. Vast amounts of new equipment were abandoned in place by the North Vietnamese as they hastily retreated.

Nevertheless, the enemy maintained some order in his withdrawal. At 0350 on 8 April, an element of the Vietnamese Army Airborne Task Force near the command post of the 3d Vietnamese Airborne Battalion was attacked. For over four hours the clash continued before the enemy withdrew leaving almost 75 dead behind. Later that afternoon, the 3d, 6th, and 8th Vietnamese Army Airborne Task Force closed in at Landing Zone SNAKE and began operations along Route 9 to the west.

The final battle of the operation took place on Easter Sunday, 14 April. The location was ironically between Hills 881 S and 881 N where the battle for Khe Sanh had started on 20 January. The 3d Battalion, 26th Marines, attacked from Hill 881 S to seize Hill 881 N and met heavy resistance. The marines prevailed, and the enemy withdrew leaving over 100 dead behind. (Map 14)

On 10 April, General Rosson had visited General Tolson, the


Map 14: Relief of Khe Sanh Operation Pegasus (Schematic No.4)

MAP 14

commanding general of the 1st Cavalry Division, and told him to begin extracting units from PEGASUS to continue preparations for the assault into the A Shau Valley. The weather in the valley was ideal for airmobile operations at the time, and General Rosson was anxious to get the new action underway before the end of the month.

The next day, 11 April, Route 9 was officially declared open at 1600. The engineers had rebuilt 14 kilometers of road, replaced 9 key bridges, and constructed 17 by-passes. General Westmoreland described their achievement as herculean.

At 0800, on April 15, Operation PEGASUS and Operation LAM SON 207A were officially ended. The 2d Brigade came under the operational control of the 3d Marine Division, joined Task Force GLICK, and initiated Operation SCOTLAND II in the vicinity of Khe Sanh. The Vietnamese Army Airborne Task Force relocated to Hue.

The rapid and successful conclusion of Operation PEGASUS can be laid first to detailed planning and preparation. Second, the enemy was either unable to, or did not know how to, react against airmobile maneuvering of large numbers of combat troops and supporting artillery around and behind enemy positions. Third, an unprecedented degree of bomber and fighter air support was provided to the ground forces, and this combat power punched the


enemy along the front line and throughout positions to his rear. Over 100,000 tons of bombs and 150,000 rounds of artillery were expended during the operation. More important, this ordnance was expended in response to excellent intelligence. Fourth, the ability to keep Khe Sanh and the troops in the field supplied was considerable. Fifth, of extreme significance was the determination and courage of the individual fighting man in the ranks.

Back to A Shau

Operation PEGASUS and the relief of Khe Sanh had been planned with an eye toward continuing the momentum of selected maneuver elements in a reconnaissance in force into the A Shau Valley. By 12 April the Provisional Corps, Vietnam, had completed a plan calling for the 1st Cavalry Division in co-operation with the 1st Vietnamese Army Division to conduct an airmobile offensive into the valley on 17 April.

During a visit to the headquarters of the Provisional Corps on 14 April, General Westmoreland chose from a hat the name DELAWARE for the operation. The plan for the operation was presented to General Westmoreland, and, while he reaffirmed his desire to go ahead with it, he disapproved the scheduled draw-down of all major units of the 1st Cavalry Division in the Khe Sanh area. General Tolson, Commanding General of the 1st Cavalry Division, General Troung, Commanding General of the 1st Vietnamese Army Division, and Major General Olinto M. Barsanti, Commanding General of the 101st Airborne Division, presented their plans for their divisions, role in Operation DELAWARE. General Rosson and General Cushman then developed a revised plan according to General Westmoreland's guidance. After a visit to the 1st Vietnamese Army Division, General Westmoreland returned to Phu Bai and approved the revised plan. The resulting operation plan 3-68 for Operation DELAWARE and Operation LAM SON 216 was published by the Provisional Corps on 16 April.

The 1st Squadron, 9th Cavalry of the 1st Cavalry Division, had been conducting extensive aerial reconnaissance in the DELAWARE area of operations during the final phases Of PEGASUS. The 101st Airborne Division and the 1st Cavalry Division published instructions to bring their plans into line with the modified Provisional Corps plan on 15 and 17 April, respectively. Extensive B-52 strikes conducted between 14-19 April preceded the initiation of the operation to eliminate antiaircraft positions located during the reconnaissance phase. The 1st Brigade, 101st Airborne Division, began moving west on 16 April and the Vietnamese Army Airborne


Map15: The Battle of A Shau Valley Friendly Situation

MAP 15

Task Force joined the 101st in moves to position units for the coordinated airmobile and ground attacks.

The operation began on the morning of 19 April. Extensive B-52 tactical air and artillery fire paved the way for the initial air assault into the A Shau Valley by the 3d Brigade, 1st Cavalry Division. Nevertheless, the antiaircraft fires that met the helicopter-borne troops were intense.

To the east, the 1st Brigade, 101st Airborne Division, began its drive westward along Route 547, shifting out of CARENTAN II into Operation DELAWARE. The 2d Battalion, 327th Infantry, attacked southwest along the road. They were followed by an air assault of the 1st Battalion, 327th Infantry, into a landing zone near the junction of Route 547 and 547 A. The next day, the 3d Brigade, 1st Cavalry Division, continued to deploy into the northern A Shau Valley as the 1st Battalion, 7th Cavalry, pushed southeast from their landing zone and the 5th Battalion, 7th Cavalry, moved


to block Route 548 which entered the valley from Laos to the west. The 2d Battalion, 7th Cavalry, began an air assault to establish a landing zone further south in the valley. The 6th Vietnamese Army Airborne Battalion airlanded into the landing zone held by the 1st Battalion, 327th Infantry, and immediately made contact with the enemy upon moving out from the landing zone. (Map 15)

On the third day of the operation, 21 April, contact with the enemy continued as the cavalry units worked deeper into the valley. just before noon, Company B, 1st Battalion, 7th Cavalry, discovered an enemy maintenance area which included a Soviet-manufactured bulldozer that was still operational. The 2d Battalion, 502d Infantry, air-assaulted into the area around the road junction to reinforce the 1st Battalion, 327th, and the 6th Vietnam Army Airborne Battalion.

During the initial days of the operation, the weather had been poor. Flying conditions were not as favorable as had been expected, and the helicopter assaults and Air Force cargo resupply missions were accomplished at no little risk to those involved. Conditions improved on 22 April and plans were advanced to assault the A Luoi airfield and the central portion of the valley. This insertion took place on 24 April when the 2d Battalion, 8th Cavalry, occupied a landing zone two kilometers south of the airfield. The 1st Brigade then began sweeping the surrounding area with the 1st Battalion, 12th Cavalry, to the south and east; the 2d Battalion, 8th Cavalry, to the south and west; while the 1st Battalion, 8th Cavalry, secured the landing zone.

To the south of the airfield a cache of sophisticated radio and wire communications equipment was found, indicating the advanced level of communications used by the enemy in the area. Other caches were discovered by the Ist Battalion, 7th Cavalry, to the north. Vehicles, ammunition, and three 37-mm. antiaircraft weapons were among the haul. Operation DELAWARE was spoiling the enemy's supply depots in the A Shau Valley.

During the rest of April, the buildup of friendly forces and supplies continued around the A Luoi airfield. The 3d Vietnamese Army Regimental Task Force joined the 1st Cavalry Division elements in exploiting the caches throughout the valley.

As the month of May came to A Shau, enemy resistance lessened while Operation DELAWARE units continued to find new enemy caches. By the end of the operation, the supplies denied to the enemy reached staggering proportions. On 2 May, the first cargo aircraft, a C-7A or Caribou transport landed at the A Luoi field, and on 4 May, a large C-130 landed. Aerial drop of supplies continued in order to fill supply stocks at the position.


The link-up between the cavalry forces in the valley and those moving west along Routes 547 and 547 A took place on 12 May. Company C, 1st Battalion, 12th Cavalry, represented the valley elements while the 3d Vietnamese Army Airborne Battalion was the lead unit in the westward moving forces. The meeting point was in the Rao Nho Valley some ten kilometers east-northeast of A Luoi and 25 kilometers southwest of Hue.

The extraction of the U.S. and Vietnamese from the A Shau began on 10 May and Operation DELAWARE terminated 17 May. The enemy had suffered over 850 casualties and had lost huge stockpiles of supplies. Any serious attempt by the enemy to conduct major offensive operations out of the A Shau base area would now require many months of additional preparation.

General Rosson labeled Operation DELAWARE:

... one of the most audacious, skillfully executed and successful combat undertakings of the Vietnam war . . . it is significant that from its inception DELAWARE was a combined effort entailing association of the 1st Cavalry Division and the 3d ARVN Regiment, 1st ARVN Division, on the one hand, and the 101st Airborne Division and the 3d ARVN Airborne Task Force on the other. The outstanding results achieved through teamwork on the part of these combined forces reflect great credit on their leadership, professionalism, and unsurpassed fighting zeal.

The A Shau Valley campaign occurred after friendly forces had been absent from that area for two years. In a way, this operation signaled an end of one phase of the conflict. It marked the loss of enemy control of a long-held fortress and also demonstrated the control which the U.S. and South Vietnamese forces were re-establishing in the wake of the enemy's Tet offensive.

page created 15 January 2002

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