U.S. Response to the TET Offensive

One of the commander's most powerful tools in influencing the outcome of any action is his personal presence at a critical time and place. As the intentions of the enemy in northern I Corps came into sharper focus, General Westmoreland on 25 January directed that a Military Assistance Command, Vietnam, Forward Command Post, be set up in the I Corps Tactical Zone. This move provided the commander with a field headquarters to observe, direct, and if necessary, control operations in the threatened northern provinces. General Creighton W. Abrams, designated Commander, U.S. Military Assistance Command Vietnam Forward, provided the requisite command presence with his arrival at the new post on 13 February 1968. Major General Willard Pearson, Assistant Chief of Staff for Operations, was designated Deputy Commander and Chief of Staff of the forward command post. About half the personnel required to staff the organization were selected from Headquarters, U.S. Army, Vietnam; 7th U.S. Air Force; and Naval Forces, Vietnam. Additional personnel came from Headquarters, Military Assistance Command, itself and from other field agencies.

The area of primary interest for the forward command post was the threatened northern provinces of Quang Tri and Thua Thien. The forward command post was established at Phu Bai near Hue. The 3d Marine Division rear echelon relocated from this site north to Dong Ha, and thus a minimum of preparation was required before the command post could move in.

Lieutenant Colonel Wallace J. Gross, deputy headquarters commandant of the forward command post, arrived at Phu Bai on 28 January to plan for the arrival of the headquarters. Colonel Gross was the first member of the new command to arrive. The next day a contingent of 17 officers and 14 enlisted men, led by Brigadier General Salve H. Matheson, operations officer for the forward post, arrived at Phu Bai. General Matheson remained in charge of the advance party until the command group arrived. The group was augmented by a communications element of the 459th Signal Battalion, 1st Signal Brigade, which arrived on 28 and 29 January. At 2045, on 29 January, communications were established between Military Assistance Command at Tan Son Nhut near Saigon and the forward command post at Phu Bai.


On 30 January, the staff of the forward command post began functioning from Room 21103 in the Military Assistance Command headquarters at Tan Son Nhut. The staff determined what additional personnel and equipment would be required to operate the forward command post, requested the principal appointments to fill these requirements, and phased personnel, supplies, and equipment into the field headquarters at Phu Bai. By 2 February, staff personnel and a headquarters support unit reported to Phu Bai. General Abrams arrived at the Military Assistance command post on 13 February and two days later assumed operational control of the 1st Cavalry Division and all other U.S. Army forces deploying to the two northern provinces. The accomplishment of organizing, activating, staffing, and deploying such a headquarters during a period of intense enemy activity was a tribute to the ability of the organizing staff.

At the command post the following priorities were promptly established: to reduce the siege of Hue, to open lines of communications and stockpile needed supplies for future operations, to receive U.S. Army reinforcements being deployed into the northern provinces from other corps, and to initiate planning for the relief of the Khe Sanh combat base.

In the ensuing weeks, the equivalent of one U.S. Army corps moved into the "heart of Marine land" and came under the operational control of the Military Assistance Command forward post. Although General Abrams was best recognized in Army circles as a tough soldier with a solid background in logistics, as the commander of the forward post he proved his other talents as a diplomat and statesman of the first rank. Enroute to his new headquarters from Saigon he visited the headquarters of the III Marine Amphibious Force and while there he and General Cushman, the Marine commander, decided the fight would be against the enemy and not an interservice one. Considering the crucial nature of the situation prevailing at the time, a surprising degree of harmony keynoted Army and Marine operations during the following months of intensive fighting.

As a modus operandi, the dispatch of messages by the forward Military Assistance Command to the commanding general of the III Marine Amphibious Force, recommended operational and logistical actions to improve the combat capabilities of forces in northern I Corps. Information copies of such messages went to the commander of the Military Assistance Command in Saigon. One example of this procedure took place during the siege of Hue and involved artillery support. General Abrams dispatched a message to the commanding general of the III Marine Amphibious Force, with an information


copy to Saigon, recommending that one battery of 8-inch howitzers be deployed from southern I Corps where enemy activity had subsided to the Phu Bai area to provide heavy artillery needed to breach the walls around the Hue Citadel. The requested battery was immediately relieved of its current mission and flown to Phu Bai in support of the operation.

The day General Abrams arrived at Phu Bai, 13 February, the decision was made to deploy the understrength 101st Airborne Division into the area of operation of the forward command post. The airborne division was minus a brigade which remained in III Corps and a battalion task force operating in II Corps. Within weeks the 3d Brigade, 82d Airborne Division, flew in from Fort Bragg, North Carolina, and came under control of the 101st Airborne Division. Another major unit programed into I Corps was the 27th U.S. Marine Corps Regimental Landing Team airlifted from California which arrived 23 February.

Planning for the Relief of Khe Sanh

As the immediate Tet emergency became less critical, the Military Assistance Command, Vietnam, Forward Command Post began to plan for the relief of Khe Sanh. This planning continued as the siege of Hue was reduced, as U.S. Army reinforcements were deployed into the area, and as lines of communication were opened and stockpiles reconstituted. When it became apparent that the logistical-over-the-shore (LOTS) supply facility could comfortably discharge over 1,000 tons a day, 1 April was set as D-day for the relief of Khe Sanh.

Before the end of February a concept for the relief of Khe Sanh was presented by the forward command post staff to the recently appointed deputy commander, General William B. Rosson, and subsequently to General Abrams and General Cushman. It was refined and used as a basis for concurrent planning by the major subordinate commands of the Military Assistance Command forward post.

On 10 March 1968 the Military Assistance Command, Vietnam, Forward Command Post was redesignated Provisional Corps, Vietnam. The following press release dated 8 March outlines the command relationships of the new headquarters:

General William C. Westmoreland, Commander of the U.S. Military Assistance Command, Vietnam, announced today the formation of a new headquarters to assist in the command and control of U.S. units in the northern part of the First Corps Tactical Zone.
The new headquarters will be commanded by Army Lieutenant


General William B. Rosson and will be designated as Provisional Corps, Vietnam. It will no doubt be more widely known to Military personnel by its short title of "Prov Corps, V."
The headquarters staff will consist mainly of Army and Marine Corps personnel, though it also will contain some Navy and Air Force officers. The new headquarters will exercise operational control of U.S. military ground units in the northern provinces of Quang Tri and Thua Thien. The Provisional Corps will be subordinate to Marine Lieutenant General Robert E. Cushman, Commanding General of the Third Marine Amphibious Force in Da Nang, who has several other senior tactical units reporting to him. It will serve as a tactical echelon between General Cushman and the Commanders of the U.S. Army and Marine Divisions in the northern area. General Cushman's area of responsibilities will remain unchanged.
General Rosson will also have coordinating functions with the highly regarded First Vietnamese Division which is deployed in the area.
Most of the personnel in the new headquarters will come from the MACV Forward Headquarters which was established in the area several weeks ago under command of General Creighton W. Abrams. General Abrams, who is General Westmoreland's deputy, has effected coordination among the Army, Navy, Marine and Air Force units in the area. Since his assigned task is virtually complete, he will now return to his normal duties in Saigon and the forward headquarters will cease to exist.

At 1201 hours, 10 March 1968, Provisional Corps, Vietnam, became operational at Phu Bai under command of Lieutenant General Rosson. The corps assumed operational control of two Army and one Marine Corps divisions and Task Force CLEARWATER, together with other combat and service support units. Major General Willard Pearson remained as the deputy commander and chief of staff, and Brigadier General Lawrence H. Caruthers assumed command of the artillery of Provisional Corps, Vietnam. Subsequently, Major General Raymond G. Davis, U.S. Marine Corps, became the deputy commander of Provisional Corps, Vietnam.

The day he assumed command, General Rosson briefed General Westmoreland on the planned operations for the corps. Three distinct operational target areas were presented: the elimination of enemy forces in the Con Thien-Gio Linh area north of Dong Ha; the opening of Route 9 with the subsequent relief of Khe San Combat Base; and an assault into the A Shau Valley. General Westmoreland approved the operations in the Con Thien-Gio Linh area to be followed immediately by the Khe Sanh operation. The A Shau operation was to be conducted as a reconnaissance-in-force operation at a later date.

The corps planned to begin the Con Thien-Gio Linh operation first and to follow it immediately, on or about 1 April, with the Khe Sanh operation. The outline for the Khe Sanh plan provided that


the 1st Cavalry Division would conduct air assaults while the 1st Marine Regiment and Vietnamese Army Task Force would execute an overland attack. At the same time, Route 547 from Hue to the A Shau Valley would be interdicted by air strikes and the valley itself subjected to additional air reconnaissance in order to locate targets for air and artillery strikes. General Westmoreland approved these plans. The Army's 1st Cavalry Division under the command of Major General John J. Tolson, III, was assigned overall operational responsibility for the relief of Khe Sanh. The offensive plan was called Operation PEGASUS after the winged horse of Greek mythology.

On 15 March, General Rosson's headquarters requested the participation of a Vietnamese Army task force in the Khe Sanh operation. This step was recommended not only for sound military reasons, but also because it was considered desirable to have major Vietnamese troops participate in the relief of Khe Sanh. A task force of three airborne battalions was made available on 28 March.

On 16 March, a logistical planning group was formed at the headquarters of the Provisional Corps to determine requirements for the offensive. The three divisions under the Provisional Corps, the 101st Airborne, the 1st Air Cavalry, and the 3d Marine were directed to send representatives, and the III Marine Amphibious Force was requested to send a representative to speak for the Da Nang Support Command, Navy Support Activity, Da Nang, and the Fleet Logistic Command.

To reduce the time required for helicopters to transfer supplies from airfields to troop field positions, airfields had to be as close as possible to operational areas. The less time required per trip, the fewer helicopters would be required. Accordingly, the planning group concluded that PEGASUS should receive logistical support from a base operated by the U.S. Army Support Command near Ca Lu. To insure continuous support, the base was to be prestocked before 1 April. To meet this goal, the logistical base was established 21 March and the next day the first of daily convoys from Dong Ha made its supply run to Ca Lu.

At Ca Lu engineers began to construct an area for an ammunition storage facility, bunkers, helicopter revetments, a road network for the supply base, fields of fire around the perimeter to improve security, and an area for petroleum, oil, and lubricants; construction of the airstrip began at the same time.

Communications planning for Operation PEGASUS indicated a need to considerably upgrade the established system. The terrain in the operational area and distances over which the signals must travel dictated that a signal hill be established. The 1st Cavalry


Division prepared and secured the complex, while the United States Army, Vietnam, and the III Marine Amphibious Force provided the needed equipment. This feat was accomplished with signal resources not under the control of the headquarters of the Provisional Corps, Vietnam. When the Military Assistance Command, Vietnam, Forward Command Post had been established, it had made do with signal support provided by other units. During February 1968, the 459th Signal Battalion had grown to support the command posts needs. When the Provisional Corps was activated, this function continued and expanded. The 459th Signal Battalion, redesignated the 63d Signal Battalion, had then assumed direct support of the headquarters of the Provisional Corps in addition to its other missions. To facilitate this change, the battalion was removed from the operational control of the 21st Signal Group at Nha Trang and instructed to answer directly to the U.S. Army's 1st Signal Brigade.

Headquarters, U.S. Army, Vietnam, directed the Provisional Corps signal officer to function as its area communications co-ordinator and representative for the northern two provinces of I Corps. This arrangement gave the Provisional Corps signal officer access to more communications support than normally available to a corps headquarters. Although somewhat unorthodox, the system proved highly efficient in actual practice.

The improvement of communications systems had earlier been extended into Khe Sanh itself. The deputy commanding general of U.S. Army, Vietnam, directed the 1st Signal Brigade to establish a tactical tropospheric scatter system from Khe Sanh. The system provided teletypewriter and voice circuits of the highest quality and the 1st Signal Brigade kept the system in service throughout the campaign.

Single Manager for Air Concept

On 8 March 1968 General Westmoreland designated his deputy for air operations, General William W. Momyer, U.S. Air Force, as the single manager for control of tactical air resources in South Vietnam to include all U.S. Marine fixed-wing strike and reconnaissance aircraft. This action was taken as a result of the buildup of Army forces in I Corps, the corresponding concentration of tactical air sorties in support of these forces, and an overriding requirement to maintain maximum flexibility in allocating air resources during the particularly critical period following the Communist Tet offensive.

A look at the statistics on the air operations supporting the


ground forces at Khe Sanh from mid-January until the end of March 1968 pointed out the need for a single focal point in co-ordinating the air effort. During this period there were nearly 10,000 Air Force fighter strikes, over 5,000 Navy and 7,000 Marine strikes, and over 2,500 B-52 strikes, for a total of more than 24,500 air strikes.

General Westmoreland's decision ran directly counter to Marine doctrine and tradition and was not welcomed by the III Marine Amphibious Force. The commanding general of the force opposed the single manager concept on the grounds that it was neither doctrinally nor functionally suited to his requirements. However, as the situation in I Corps changed, the concept was implemented on 10 March 1968 as approved by the Pacific commander in chief. The system actually became effective about 1 April 1968.

Integrated with the tactical air operation was the air resupply of troops at Khe Sanh. The following table shows the number of personnel and tons of supplies airlifted into Khe Sanh in March 1968.

Date Short Tons Personnel
3 March 193 30
4 March 184 73
8 March 219 21
9 March 201 36
10 March 195 116
16 March 172  
17 March 243  
20 March 292+448 barrels POL  
21 March 247+554 barrels POL  
23 March 232  
24 March 233  
25 March 149  
26 March 149  
27 March 161  
28 March 148.6  
29 March 235  
30 March 240  

Clearly the close air support and air resupply by the U.S. Air Force and Marine Corps as well as helicopter supply operations by the U.S. Army played a major role in the defeat of the North Vietnamese Army during the Khe Sanh operation.

page created 15 January 2002

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