Indochina Monographs


by Maj. Gen. Nguyen Duy Hinh

Published by U.S. Army Center Of Military History



by Maj. Gen. Nguyen Duy Hinh


The Planning Phase

How It All Started

To the South Vietnamese political and military leaders, the Ho Chi Minh Trail had always been like a thorn in the back to be removed at any cost whenever there was a chance. The possibility that something could be done about it began to take shape as the war intensified and U.S. combat forces helped regain the military initiative in 1966.

One of the leading Vietnamese strategists, General Cao Van Vien, who was both Chairman of the Joint General Staff and Minister of Defense at that time, was the first to advocate the severance of the Communist lifeline. In a testimony given before members of the National Leadership Committee, who ruled the country from June 1965 to September 1967, General Vien propounded an offensive strategy, called the "strategy of isolation and severance" for the effective defense of South Vietnam. This was in essence a two pronged strategy aimed at isolating the Communist infrastructure and guerrillas from the population within South Vietnam by pacification on the one hand, and severing North Vietnam's umbilical cord with its southern battlegrounds on the other. To implement this severance action, he proposed to invade North Vietnam's southern panhandle with the objective of seizing the city of Vinh, the northern terminal of the Ho Chi Minh Trail, and at the same time establishing a strong defense line across northern Quang Tri Province to run the entire length of National Route No. 9 from the eastern coast to the Mekong River bank. This operation assumed the participation of U.S. and other Free World Military Assistance Forces. The attack against the two southernmost North Vietnamese provinces - Thanh Hoa and Nghe An - and their

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eventual occupation, would serve as leverage for bargaining in truce negotiations while the defense line along Route No. 9 would give the RVN a reasonable chance to defend itself after its forces would have been withdrawn from North Vietnam's panhandle. Such was the general outline of General Vien's strategy which subsequently became the widely commented subject of several lectures and magazine articles. (1)

General Vien's concept remained only that because South Vietnam was unable to perform this momentous task all by itself.

In early January 1971, General Crighton W. Abrams, COMUSMACV, called on General Vien at the JGS and suggested an operation into lower Laos. With the unrealized concept still nurtured in his mind, General Vien gladly agreed. Meeting with General Vien again a few days later, General Abrams explained his concept of the operation on a map. U.S. forces were to clear the way to the border by conducting an operation inside South Vietnam. The main effort was to be conducted by RVNAF airborne and armor forces along Route No. 9 in coordination with a heliborne assault into Tchepone. The purpose was to search and destroy base area 604. Other RVAAF units would be employed to cover the northern and southern flanks of the main effort. For the support of the operation, maximum U.S. assets would be provided. After searching and destroying base area 604, ARVN forces would shift their effort toward base area 611. At the end of the meeting, both General Abrams and General Vien agreed to have staff officers work out an operational plan.

General Vien then reported his discussions with General Abrams to President Nguyen Van Thieu because he knew this cross-border operation was going to have international repercussions. Being a military man himself and well versed in military strategy, President Thieu immediately approved the operation.

Recognizing the political realities, General Vien had long since abandoned the idea of an invasion of North Vietnam as part of an operation to sever the Ho Chi Minh Trail, but still his concept differed somewhat from that presented by General Abrams. General Vien advocated

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an airborne operation into Tchepone as the first step. Then after searching, the paratroopers would attack east to link up with an armor-infantry task force moving along Route No. 9. After link-up, the forces could shift their effort southward toward base area 611. General Vien conceived the foray into Laos to be a raid, an operation of short duration and ordered his J-3 to look for drop-zones around Tchepone. Later, because he felt he should go along with the MACV concept in order to obtain the necessary U.S. support assets, he abandoned this concept and did not even discuss it with General Abrams.

In mid January the J-3, JGS, Colonel Tran Dinh Tho, and his MACV counterpart flew to Da Nang. Colonel Tho's mission was to brief Lieutenant General Hoang Xuan Lam, Commander of I Corps and MR-l on the concept of the operation. The meeting took place discreetly at Headquarters, US XXIV Corps. General Lam was taken to a private briefing room where, in front of a general situation map, Colonel Tho explained how the operation was to be conducted as conceived by the Joint General Staff(2). The main effort of the operation, he said, was to be launched along National Route No. 9 into Laos with the objective of cutting the Ho Chi Minh Trail in the region of base area 604 and destroying all enemy installations and supplies stored there. After this mission had been accomplished, the operational forces were to move south and sweep through base area 611 to further create havoc to the enemy's logistic system before returning to South Vietnam. This operation was to be conducted and controlled by the I Corps Command which, in addition to its organic units, would be augmented by the entire Airborne Division and two Marine brigades. The third Marine brigade and the Marine Division Headquarters would be available if required. As to U.S. forces, they were going to conduct operations on the RVN side of the border and provide the ARVN operating forces with artillery, helilift and tactical air support. This concept of operations thus coincided in near totality with the one initially proposed by COMUSMACV.

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After this exclusive briefing, General Lam met in private with Lieutenant General Sutherland, Commander U.S. XXIV Corps. General Sutherland's staff had already begun planning after receiving the MACV directive on 7 January, but now joint planning could begin in earnest. A joint planning committee with strictly limited membership began working on the operational plan at the headquarters compound of U.S. XXIV Corps. The only I Corps staff members involved were the G-3 and the G-2. On the U.S. side, the same restriction on the planning staff was initially observed. Both staffs worked closely together in a specially arranged area with limited and controlled access.

On 17 January, planning guidance was provided by I Corps and U.S. XXIV Corps to participating units under the guise of "Plans for the 1971 Spring-Sumer Campaign" and on 21 January, General Lam and General Sutherland flew to Saigon, where, during a meeting at MACV Headquarters, they submitted the plan to the Chairman of the JGS and the MACV Commander(3). Intelligence estimates on which the detailed operational concept was formulated were also carefully reviewed. Subsequently on the same day, General Lam personally presented his operational plan to President Thieu.

The Basic Operational Plan

The combined operation was code named LAM SON 719(4). It was to be executed in four phases during an indefinite period of time with the objective of destroying enemy forces and stockpiles and cutting enemy lines of communications in base areas 604 and 61l. (5)

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Operation Plan, Phase I (Dewey Canyon II)
Map10: Operation Plan, Phase I (Dewey Canyon II)
In Phase I, which was to be called Operation Dewey Canyon II, the 1st Brigade, U.S. 5th Infantry Division (Mechanized), reinforced, was to advance on D-Day, occupy the Khe Sanh area, and clear Route No. 9 up to the Laotian border, ARVN troop assembly areas, and forward artillery positions required for support of the operation (Map 10). In the meantime, the U.S. 101st Airborne Division (Airmobile), while continuing its operations in Thua Thien and Quang Tri Provinces, was to conduct artillery attacks by fire in the A Shau Valley, west of Thua Thien Province from D-Day to D+4 (a diversionary action) and in cooperation with the 2d Regiment, 1st ARVN Infantry Division to be prepared to defend the areas south of the DMZ. The U.S. 45th Engineer Group was assigned the mission to repair Route No. 9 up to the Laotian border and rehabilitate the Khe Sanh airstrip for C-130 use. Tactical air was to be provided by the U.S. 7th Air Force, B-52 strikes by CINCSAC, and gunships and artillery by units of U.S. XXIV Corps. During Phase I, ARVN forces were to complete their movements toward assembly areas and be prepared to attack on order across the border into lower Laos.

Operation Plan, Phase II
Map11: Operation Plan, Phase II
In Phase II, on D-Day, I Corps forces, following intensive preparation fires, were to launch their attack into lower Laos. The major effort was to be conducted along Route No. 9 by the ABN Division reinforced by the 1st Armor Brigade, engineer and artillery elements. While the 1st Armor Brigade (with its two squadrons 11 and 17) and engineer troops moved along Route No. 9, repairing it as they progressed, en ABN battalion was to be helilifted into Objective A Luoi (geographical name: Ban Dong) and two other ABN battalions were to establish fire support bases - one eight kilometers northwest and the other eight kilometers northeast of A Luoi - to the north(Map 11). Battalions of the 1st Infantry Division's 1st and 3d Regiments were to be inserted by helicopter and establish FSBs on the Co Roc elevation south of Route No. 9 to protect the I Corps southern flank. The 1st Ranger Group with its three battalions, the 21st, 37th and 39th, was to be helilifted north of Route No. 9 to occupy blocking positions more than 16 kilometers to the northeast of A Luoi and protect the northern flank of the ABN Division. After the completion of this troop movement, the armor brigade would attack westward from Objective A

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Luoi to link-up with the third ABN Brigade which was to be helilifted into Tchepone. The Marine 147th and 258th Brigades would serve as I Corps reserves at Khe Sanh.

Also during Phase II, the U.S. 1st Brigade, 5th Infantry Division (Mechanized) was to continue operations west of Quang Tri Province and the U.S. 101st ABN Division (Airmobile) was to continue security operations as during Phase I and provide reinforcements and combat support as required. The ARVN "Black Panther" (reconnaissance) company, 1st Infantry Division, in the meantime, was to be attached to the U.S. 101st ABN Division and employed in rescue missions, if required, to extract U.S. crew members shot down in Laos.

Phase III was to be initiated after the successful occupation of Tchepone. It was to be the exploitation phase during which search operations would be expanded to destroy enemy bases and stockpiles. The ABN Division would search the area of Tchepone while the 1st Infantry Division would conduct search operations to the south. The 1st Ranger Group, meanwhile, would continue holding blocking positions to the north. During Phase III, the mission of U.S. forces was unchanged; they would continue to provide fire support, helilift and tactical and strategic air for ARVN units.

Phase IV was the withdrawal phase. On order, I Corps forces were to withdraw toward the border by one of two alternate routes called Options 1 and 2. In Option 1, the ABN Division and the 1st Armor Brigade were to withdraw to Objective A Luoi to support and cover the 1st Infantry Division which was to attack and search the western part of base area 611 then move on southeastward, followed by the ABN Division. In the meantime, the 1st Armor Brigade, augmented by the 1st Ranger Group from its northern positions and having been separated from the ABN Division, was to withdraw toward Khe Sanh along Route No. 9. The Marine 147th and 258th Brigades were to conduct operations into the Laotian salient toward Objective Ngok Tovak at the same time as the 1st Infantry Division began its attack to the southeast. Option 2 differed from Option 1 only during the last stage of the withdrawal when, after sweeping through base area 611, the 1st Infantry Division, to be followed by the ABN Division, was to

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change direction and move eastward through the Laotian salient toward an area near Route No. 9. The mission of U.S. forces during this final phase was to remain unchanged.

On 22 January, XXIV Corps and I Corps completed preparation of their operational orders. On D-Day, 30 January the Forward CP of I Corps was to be established at Dong Ha; it was to include a small command element to be located at Ham Nghi FSB, south of Khe Sanh. The Forward CP of the U.S. XXIV Corps was to move to Quang Tri combat base the day before. The I Corps forces were to cross the border on 8 February. During a combined briefing session held at Dong Ha on 2 February, the I Corps operation orders were disseminated to all participating units (6). (Chart 1)

Task Organization, LAM SON 719, Early February 1971
Chart1: Task Organization, LAM SON 719, Early February 1971

To assist in the execution of LAM SON 719, MACV planned a diversion in the form of a maneuver involving U.S. naval and marine units off the coast of Thanh Hoa Province (North Vietnam).

Division Planning and Preparations

The main effort of LAM SON 719 was assigned to the Airborne Division and on 18 January 1971, during a meeting at I Corps Headquarters, the division commander, Lieutenant General Du Quoc Dong, learned this for the first time. He immediately ordered his division, at the ABN Division rear base in Saigon to begin preparations for deployment. Meanwhile, the U.S. advisory team on 27 January visited headquarters, U.S. XXIV Corps, to receive first hand briefings and report on ABN preparations. ABN units deployed on an operation in War Zone C (north of Tay Ninh) were withdrawn to receive additional training by U.S. advisers on communications and the employment of U.S. gunships and supply and medevac helicopters, as well as air-ground communications with supporting U.S. tactical aircraft.

General Dong flew to Dong Ha on 1 February 1971 and was followed during the next few days by his staff, the U.S. ABN Division advisory team, and combat and support units.

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The ABN Division began its operational planning only after it received detailed guidance from the I Corps commander on 2 February during the combined staff meeting at Dong Ha, where the I Corps Forward CP was now located.

The combat plan developed by the Airborne Division called for successive heliborne operations to occupy Objectives 30, 31 and A Luoi in coordination with an armor-infantry thrust along Route No. 9. Intermediate objectives, on which fire support bases would be established, would be seized in the advance to Tchepone, after which battalion sized blocking positions would be occupied around Tchepone. The heliborne operations to occupy A Luoi and Tchepone would be conducted as soon as the armor-infantry thrust progressed near the objectives. This was to be a coordinated advance so timed as to provide immediate link-up at the objectives. (Map 11)

Initially, the armor-infantry thrust consisted of two squadrons, the 11th and 17th of the 1st Armor Brigade, the 1st Airborne Brigade (with its three battalions: 1st, 8th and 9th), the 44th Artillery Battalion (155-mm) and the 101st Engineer Battalion. This task force was to advance along Route No. 9, repair roads as it moved and link-up with heliborne units. The 3d Airborne Brigade (three battalions: 2d, 3d and 6th) would be the heliborne force assigned to occupy objectives and establish FSBs north of the road. For the assault on Tchepone, the mission was given to the 2nd Airborne Brigade which consisted of three battalions, the 5th, 7th and 11th. The troop pick-up point for airborne operations would be Ham Nghi Base. The Airborne Division operation plan was presented to Lt. General Hoang Xuan Lam on 3 February who immediately approved it in principle.

Of the two Marine brigades to be provided by the JGS, the 258th Brigade with one artillery and three infantry battalions was operating in an area southwest of Quang Tri. The other brigade, the 147th after regrouping its detached units, completed its movement by C-130 to Dong Ha on 3 February. Both brigades were to be employed as I Corps reserves and given the temporary mission of security for ARVN forces on the RVN side of the border.

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The I Corps organic forces that participated in the operation were the 1st Infantry Division, 1st Ranger Group and 1st Armor Brigade, all immediately available. The 1st Armor Brigade with its two squadrons was attached to the Airborne Division. The 1st Ranger Group was assigned the security mission on the northern flank of the operational area. Its three lightly equipped battalions would be deployed in screening positions facing north (7). The 1st Infantry Division, meanwhile, would deploy its two regiments, the 1st and 3d, to its area of operation south of Route No. 9 with the mission of blocking enemy forces from the south and simultaneously searching enemy base area 611. Its two other regiments, the 2d and 54th, which would not participate in the operation, but would remain where they were, east of the DMZ area and west of Hue, respectively.

U. S. Support

It was apparent that due to the lack of helicopters, tactical air and long range artillery, I Corps could not conduct such a large scale operation away from its support bases without assistance. United States support was therefore required, not only to compensate for I Corps' lack of assets but also to provide the kind of mobility and firepower needed for combat against a heavily defended enemy stronghold in rugged terrain. Therefore, the U.S. XXIV Corps was charged with planning for this substantial support.

An outstanding feature of LAM SON 719 was the conspicuous absence of U.S. combat troops and U.S. advisers who were not authorized to go into

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lower Laos. U.S. advisers could still provide assistance to ARVN staffs but only at command posts located on the RVN side of the border. Even division senior advisers were not authorized to fly over lower Laos(8). To compensate for the absence of advisers who always helped in communicating with U.S. units for support, it was decided to assign a Vietnamese serviceman-interpreter to each of the FAC teams and to the 7th Air Force airborne command and control center. It was also planned that one member of each division advisory team would be airborne over the AO of their respective units. This was intended to alleviate some of the problems related to language and communications.

The U.S. 108th Artillery Group received the mission of augmenting the firepower of I Corps Artillery. This group consisted of the 8th Battalion, 4th Artillery (with four 8-inch howitzers and eight 175-mm guns), the 2d Battalion, 94th Artillery (with the same number of artillery pieces), and B-Battery, 1st Battalion, 396th Artillery (with four 175-mm guns). As required, the 108th Artillery Group could be augmented by the 5th Battalion, 4th Artillery (with eighteen 155-mm self-propelled howitzers), which was the direct support unit of the U.S. 1st Infantry Brigade (Mechanized).

Procedures for coordination and liaison were clearly established. Fire coordination was to be effected at I Corps FSCC between fire support elements of I Corps and XXIV Corps, and communications with I Corps artillery was to be maintained through U.S. advisers. Plans were also made to provide for close coordination between supporting and supported units. This was done by an exchange of liaison officers between the U.S. 108th Artillery Group and ARVN infantry divisions and brigades operating separately. Fire support requests from ARVN units in Laos could be routed through either one of two alternate channels. The first channel was from requesting units to division or separate command posts where the U.S. 108th Artillery Group's liaison officers would receive and

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forward all requests to supporting units. Through the second channel, operational units were able to send fire support requests directly to their liaison officers posted at the U.S 108th Artillery Group CP where the requests would be immediately routed to the fire direction centers (FDC) of supporting units. Fire coordination with the U.S. 4/77 Aerial Artillery Battalion was to follow the same channels as those of the 108th Artillery Group to which the battalion would attach liaison officers to collect fire data or requests.

Of prime importance to the entire operation was the mobility support provided by United States helicopters of all types. The U.S. 101st Airborne Division (Airmobile) was assigned this support responsibility. Having to continue its current missions inside South Vietnam which were greatly expanded due to the redeployment of a number of ARVN units and to provide operational support in lower Laos at the same time, the 101st Airborne Division obviously could not meet all the requirements with its organic assets, so the division was augmented with four Assault Helicopter Companies (UH- lH), two Assault Support Helicopter Companies (CH-47), two Air Cavalry Troops and two Assault Helicopter battalion headquarters, all detached from other U.S. divisions. This reinforcement was to be more substantial on days when special requirements arose. Each U.S. assault helicopter battalion was made responsible for providing direct support to an ARVN major unit. Thus the 158th Assault Helicopter Battalion was assigned to support the ARVN Airborne Division and its reinforcements and the 223d Combat Assault Battalion was to pr6vide support for the ARVN 1st Infantry Division while the 14th Combat Assault Battalion would support the Vietnamese Marine brigades. Each of these support battalions was to attach a liaison team to the ARVN unit to be supported and each U.S battalion commander was required to visit the ARVN unit he supported every day. In case additional support units were provided, they would be placed under the operational control of these commanders. The commander of the 101st Aviation Group, 101st Airborne Division was to exercise operational control over all assault, assault support and aerial weapons helicopter units (Chart 2). In addition, an Assistant Commander of the 101st Airborne Division was designated as the aviation support coordinator.

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U.S. Army Aviation Task Organization
Chart2: U.S. Army Aviation Task Organization

To solve problems related to tactical air support, certain flexible arrangements were made. An airborne command and control center of the United States 7th Air Force (AFCCC) was to operate around the clock aboard a C-130 aircraft to receive support requests, provide guidance for preplanned tactical air sorties, to make decisions on the employment of assets, and to ensure that additional sorties would be available in case of emergency. All forward air controller (FAC) teams, each assigned a Vietnamese interpreter, were to cover the areas of operation assigned to ARVN divisions and separate brigades. Initially, 200 tactical air sorties were planned for, each day. Emergency tactical air support requests would be initiated by ground units and sent to the airborne FAC team which would relay them to the 7th Air Force AFCCC, also airborne, for immediate action. Preplanned sorties would have to be requested through the normal channel which went from the Tactical Air Control Parties (TACP), attached to ARVN divisions, to I Corps Fire Co-ordination Control Center/Direct Air Support Center (FSCC/DASC) and from there to the XXIV Corps Forward Direct Air Support Center at Quang Tri. To facilitate air support missions in bad weather or at night, an air support radar team (ASRT) of the U.S. Marines at Quang Tri would be provided at Khe sanh from where it could cover the entire area of operation in lower Laos. A number of U.S. naval air sorties to be launched from aircraft carriers USNS Hancock, Kitty Hawk and Ranger was also planned. Finally, LAM SON 719 was to receive the highest priority in strategic air sorties provided by the Unites States Strategic Air Command.

Solving Logistic Problems

In addition to combat and combat support planning, an important area that required extensive pre-arrangements was logistics. Unfortunately, the ARVN 1st Area Logistics Command, which was responsible for logistical support for I Corps and MR-l, was excluded from the operational planning staff because of security and restrictive measures. Therefore, when this, logistic command received orders to make preparations

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for support, it was too late. But this tardiness was in no way an insurmountable obstacle. A big, helping hand was extended by the U.S. Army Support Command, Da Nang. U.S. support and the division of tasks between U.S and ARVN logistics units were planned as follows:

U.S. Army Logistic Plan, LAM SON 719
Map12: U.S. Army Logistic Plan, LAM SON 719
from D-day to D+8 I Corps units were to receive the same support from U.S. logistic agencies as United States units. During the period from D+9 to D+17 the ARVN 1st Area Logistics Command was to gradually take over responsibility for the support of operational forces. U.S. logistic agencies would be deployed to the assembly area ahead of time and would initiate support activities when the operation was launched. Under the delegation of authority from and with reinforcements provided by the Da Nang Support Command, the U.S. 26th General Support Group (GSG) was to establish a base support area (BSA) at Quang Tri to be operational on D-Day. Two forward logistic agencies were also to be established: Forward Support Area (FSA) 26-1 in the Ca Lu - Vandegrift area to begin operations on D-day, to be followed by FSA 26-2 at Khe Sanh which would become operational during the period from D+4 to D+6. (Map 12)

During the initial period, no significant difficulties were encountered by U.S. logistic units in supplying ARVN forces because most supply items were similar with the exception of some special types of ammunition, for example 57-mm recoilless, and more particularly, combat rations. The ammunition items were no longer available in the U.S. supply system and ARVN combat rations were radically different from U.S. C-rations. As a result adequate ARVN combat rations were immediately shipped to class I supply points operated by United States forward support areas.

ARVN Logistics Plan, LAM SON 719
Map13: ARVN Logistics Plan, LAM SON 719
On its part, the ARVN 1st Area Logistic Command planned to establish three main support areas at Phu Bai (near Hue), Quang Tri and Khe Sanh(Map 13). To facilitate coordination of activities and the maintenance of security it was decided that U.S. and ARVN logistic agencies would be co-located and there should be an exchange of liaison officers as well as logistic data between the two staff elements at Da Nang and in forward support areas.

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The most vital consideration in logistic support planning was supply routes and transportation. The major axes of road communication available were Routes No. 1 and No. 9. While No. 1 was a two way all weather road from Da Nang to Dong Ha, truck traffic from the Dong Ha junction had to move westward on No. 9. This was possible only to Vandegrift base. From Vandegrift to the Laotian border, No. 9 was extensively damaged with many destroyed bridges. Therefore, U.S. engineer units were charged with repairing and rehabilitating this stretch of road. The control of traffic movements on Routes No. 1 and 9 would require very close coordination between U.S. and ARVN traffic management agencies.

Integrated Transportation System, LAM SON 719
Map14: Integrated Transportation System, LAM SON 719
In sea transportation, the port of Tan My and the Dong Ha ramp, about 8 miles upstream from the Cua Viet rivermouth, were to serve as major shipping points. Both facilities were operated by U.S. forces. Most ARVN supplies would be shipped by LST to Tan My where they would be unloaded with the assistance of U.S. terminal personnel. For the shuttle of supplies between Tan My and long Ha, a number of American intercoastal ships would be used to assist the ARVN 1st ALC. (Map 14)

In air transportation, the two existing airfields at Quang Tri and Dong Ha were ready for immediate use. The abandoned airstrip at Khe Sanh, however, needed extensive repairs by U.S. engineer units and was scheduled to become operational on D+6 to accommodate C-130 cargo planes. Several U.S. C-130 planes were also earmarked for the ARVN to transport emergency supplies directly to Khe Sanh. Due to the sizable quantity of helicopters required to support the operation, the supply of aviation fuel was an important problem. ARVN quartermaster units were assigned additional assets for the transportation of fuels, and the establishment of forward storage facilities and supply points.

To move supplies to forward combat units operating along Route No. 9, ground transportation was planned. For those units operating far from the road, helicopters would be used both for re-supply and medical evacuation. As to the movement of heavy items of supply to forward areas, the only means available would be large U.S. cargo helicopters.

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The entire planning process - and the resultant operations plan - for LAM SON 719 indicated a carefully considered decision arrived at by responsible U.S. and GVN political and military authorities. The authorities of each country - the US and the GVN - considered in their decisions the best intelligence available to them at the time and each approached the problem with the best interests of his own country in mind. Of course each was influenced by the political and military factors peculiar to his own country. Tchepone, the crossroads of enemy supply routes, appeared to be a well selected objective since all enemy logistic and infiltration movements south had to go through this area. According to intelligence reports, this was indeed an area where important enemy storage facilities were located. The time had finally arrived to sever by ground attacks the lifeline which had sustained enemy warring capabilities for so many years. This was a sound and bold decision following several years of reconnaissance and interdiction efforts from the air.

The time frame selected for the operation was also appropriate in that the dry season in the Laotian panhandle had begun three months earlier. After his substantial losses in Cambodia during 1970, the enemy was using the dry season to the maximum for the movement of replacements south and to replenish his supplies; the enemy was conducting an aggressive "logistic offensive." The amount of supplies in transit and in these storage facilities was substantial and if we succeeded in destroying them, the blow on the enemy would be most devastating. He would be in serious trouble, not only from our spoiling actions during the remaining three months of the dry season, but also because time was running out for the movement of supplies for that year.

Despite the continuation of redeployments, United States military presence in South Vietnam was still substantial enough to support a large scale offensive by the ARVN. If this offensive were deferred, U.S. support would no longer be as adequate and as effective. This was

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another consideration of prime importance which contributed to the decision to conduct LAM SON 719 at this time.

Once the decision was made, the speed with which planning and preparations progressed was amazing. Only two weeks after planning guidance was received, operational orders had been developed by I Corps and XXIV Corps. This was indicative of how close and effective cooperation and coordination between U.S. and ARVN staffs had been.

The exchange of intelligence proved to be particularly beneficial to ARVN forces. Lacking long range reconnaissance facilities, the ARVN intelligence system could not provide adequate data on the Ho Chi Minh trail and North Vietnam. It was obvious that almost all information concerning enemy capabilities in the target area had to be supplied by the United States.

Combat support provided by the U.S. XXIV Corps for I Corps was another indication of the outstanding support provided by MACV. The I Corps unit commanders who were to participate in the operation felt encouraged and unusually enthusiastic because of this. To them, this was an opportunity not only to prove I Corps combat effectiveness but also to compete with their colleagues of III and IV Corps who had participated in the Cambodia incursion the previous year. Finally, the fact that no U.S. combat troops were to cross the border and that even U.S. advisers were precluded from the operation made the role of ARVN units even more prominent.

In spite of the sound decision, the effective cooperation and coordination between the RVNAF and MACV and the support allocated by the United States, several problem areas cropped up during the planning phase which should receive special attention. First, the entire process of planning and operational preparations appeared to have taken place in a great rush. Considering the scale of the operation and the importance of the objectives, the time involved for planning might have been too short. To ensure utmost secrecy, participating units were given only a short time to prepare. In the face of such a difficult campaign which was to be conducted over unfamiliar terrain, the question that naturally arose was: were I Corps units prepared to

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meet all the unforeseeable challenges? The events that subsequently occurred during the operation left no doubt as to the answer to this question. Then there was the questionable wisdom in selecting a single road axis for the major effort of the offensive. Hemmed in by dense jungle and rough mountainous terrain, this type of road did not lend itself readily to heavy logistic activities. In South Vietnam, such difficulties in road transportation could be removed by the alternate use of waterways or U.S. airlift facilities. But in lower Laos, jungles, rough mountains and steep valleys, added to the stubbornness of the enemy, created serious problems that should have received more attention. While there were plans for infantry units to advance and withdraw using different routes, mechanized and armor units were confined to Route No. 9. The holding of this route required the relative superiority of friendly forces, which was not the case.

Next was the tactic of establishing fire support bases. In view of the single axis available to progress through mountains, the effective control of the area of operation and the conduct of search activities depended on the capability of our forces being deployed on both sides of the road, north and south. In our case, the operational plan called for the advance of infantry forces through a series of fire support bases. Each new leap forward necessarily required an additional number of these bases. The use of fire support bases had been successful in South Vietnam but this success depended a great deal on the over-whelming firepower and initiative of United States forces in the face of a less endowed enemy. To be effective in lower Laos, it was apparent that fire support bases would have to enjoy the same conditions. The question was: would it be feasible? If it was not - without the benefit of firepower and initiative in the area of operation - fire support bases were apt to become defensive positions tying down sizeable forces which otherwise might be used for offensive.

A comparison between friendly and enemy forces in lower Laos also resulted in hard thinking even during the initial phase. As intelligence estimates had made it clear, enemy forces in the area of operation included three infantry regiments, not to mention the eight or so binh

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trams, each equivalent to a regimental size force in terms of ground defense and antiaircraft capabilities. Within a period from one to two weeks, the enemy was capable of reinforcing with up to a total of eight additional infantry regiments, not to mention artillery and other units from North Vietnam. To defeat these 11 infantry regiments and the defense forces of the binh trams, I Corps committed, according to the initial plan, only eight infantry regiments or brigades. Our forces enjoyed the advantage of an armor brigade but our tanks might be of little value off the main axis. Even if, at the limit of its capabilities, I Corps would bring in two additional regiments (the remaining Marine brigade and the third regiment of the 1st Infantry Division), it would only have 10 regimental size units and the balance would still be in favor of the enemy. Additional reinforcements would be highly improbable and any such effort to obtain them would certainly meet with difficulties.

In the effort to obtain the tactical advantage in the area of operations and to compensate for the lack of force superiority, the planners of LAM SON 719 expected too much from the support of United States tactical air and air cavalry gunships. The question that should have been asked then was: how effective would air power be in support of ground combat troops deep in the Truong Son mountain range? If the bombings of North Vietnam had been an indication of this effectiveness, then were the results to be obtained exactly what we had desired? Over the years, the U.S. Air Force had bombed the Ho Chi Minh trail heavily. Was the effect of these bombings enough to paralyze the enemy's activities on the battlefields of South Vietnam and Cambodia? Too much was expected from airpower and this problem should have been weighed with caution by the planners.

Then there was the role to be played by helicopters. With the exception of mechanized forces operating along Route No. 9 which would be re-supplied by road transportation according to plans, all other operational units would have to depend on helicopters for movement of troops and artillery, supply and medical evacuation. This was the only means practicable as long as these forces were required to operate considerable distances from roads and fire support bases. There was no doubt that

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the U.S. would provide enough helicopters to satisfy requirements. But there was cause to doubt the effectiveness of helicopters in the expected combat situation, considering the terrain and weather in lower Laos and the enemy's antiaircraft capabilities. This was a serious question which required careful consideration.

As the time approached for D-day, however, ARVN and U.S. commanders and staffs alike appeared to be confident of success. As a testimony to this confidence, I think it appropriate to excerpt here a passage of the report filed by Colonel Arthur W. Pence, senior adviser of the Airborne Division. In this after- action report, Colonel Pence described the mood that prevailed during a meeting at Headquarters, U.S. XXIV Corps prior to Phase I of LAM SON 719. He wrote:

"It was apparent at this time that United States intelligence felt that the operation would be lightly opposed and that a two day preparation of the area prior to D-Day by tactical air would effectively neutralize the enemy antiaircraft capability although the enemy was credited with having 170 to 200 antiaircraft weapons of mixed caliber in the operational area. The tank threat was considered minimal and the reinforcement capability was listed fourteen days for two divisions from north of the DMZ." (9)

The RVN military leaders thought that ARVN forces had a tough mission ahead but would be able to carry it out with the support of the United States. The decision had been made. I Corps forces were like the soldier on the firing line who had armed his rifle and taken aim. All he had to do now was to squeeze the trigger.

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(1) "Vietnam: What Next? The Strategy of Isolation," Military Review, April 1972.

(2) After the exclusive briefing for General Lam, Colonel Cao Khac Nhat, G-3 I Corps, took Colonel Tho aside and told him, "Why exclude me from the briefing? I have already completed the operational plan."

(3) This date was obtained from U.S. XXIV Corps After Action Report which records: "21 January: XXIV Corps/I Corps received approval of detailed concept." Ibid. p.3.

(4) Lam Son was the birthplace of Le Loi, a national hero second only to Tran Hung Dao in popular reverence. Le Loi ejected the Chinese from Vietnam in the early 15th Century.

(5) The directive given by U.S. XXIV Corps to the U.S. 101st Airborne Division (Airmobile) and the Da Nang Support Command stated that these units should be prepared to provide support for I Corps operations forces for at least 90 days, in other words, until the onset of the Laotian rainy season in early May 1971.

(6) For details on participating units, see Appendix A.

(7) General Lam considered the Ranger Group adequate for this mission, which was to provide the main body early warning of any enemy force approaching on his flank and to delay and force him to concentrate until heavier combat power could be placed against him. It would have been advantageous to assign this mission to a mobile, armor equipped force, but not only did the rugged terrain preclude this, but General Lam needed his armor and his 1st Division for the main effort. Furthermore, he wanted to keep the 1st Division available for a sweep south through base area 611.

(8) After Action Report on LAM SON 719; 1 April 1971, by Colonel Arthur W. Pence, p. 3.

(9) After Action Report on LAM SON 719 dated 1 April 1971 by Colonel Arthur W. Pence, p. 2.