UNCOMMON GROUND: THE MARINES AND U.S. ARMY IN I CORPS

From Vietnam Magazine, October, 1999, pp. 22-28

©1998 by Peter Brush

American military commanders sought to present a united front, to speak with one voice, regarding the successes of U.S. military efforts during the Vietnam War. This unanimity, however, was more apparent than real. To the extent it was successful, moreover, it minimized the very fundamental differences that existed between the U.S. Army and Marine Corps as to the most effective method of waging war in Vietnam.

Over time these differences became acute. On January 22, 1968, the commander of American forces in Vietnam, General William Westmoreland, sent a TOP SECRET cable to General Earl Wheeler, Chairman of the U.S. Joint Chiefs of Staff (JCS). This cable noted that the professionalism of the Marine Corps in Vietnam had fallen "far short of the standards that should be demanded by our armed forces" and that Marine performance throughout their ranks required "improvement in the national interest." 1 What caused this polarization? An examination of the differences between U.S. Army and Marine Corps military doctrine in Vietnam furnishes some clues.

Military doctrine may be defined as the distillation of collective wisdom that the institutional leadership uses to effect the ways in which the military executes and plans training and operations. 2 U.S. Army doctrine in the 1960's was forged from its successes in the conventional wars of the twentieth century, and modified by the political realities of limited war as waged in Korea. The U.S. Army rode these successes into the battlefields of Vietnam. 3 Limited war, by definition, places constraints on the use of military resources, constraints that are lacking in conventional wars. The superiority of U.S. firepower and technology in World Wars I and II were incorporated into the doctrine employed in the Korean conflict: massive firepower and the attrition of Communist forces. Although failure in war may incline an army to question the efficacy of its doctrine, the U.S. Army was not so inclined in Vietnam. It was not conceivable that an army capable of defeating both Japanese militarism and Nazi fascism would be inadequate to the task of defeating Vietnamese communism.

In June 1954, the U.S. received permission from France to participate in the training of the Vietnamese armed forces. When the French expeditionary force withdrew from Indochina in 1956, the U.S. Military Assistance Advisory Group saw its goal primarily as one of creating a conventional army of divisional and supporting units of the Vietnamese National Army (VNA, later ARVN). The divisional force structure of the ARVN was organized to deal with a Korea-style invasion from North Vietnam. U.S. Army Tables of Organization and Equipment were translated into Vietnamese and issued to the ARVN with no major variations. By 1959, the ARVN had seven standard divisions (plus armored cavalry) which closely paralleled U.S. Army units in World War II. 4

The administration of U.S. President Kennedy brought a change from the massive retaliation strategy favored by President Eisenhower to one of flexible response, which would meet aggression at any level of violence. Kennedy correctly saw that insurgencies were the preferred mechanism by which the Communists would attempt to spread their influence in future wars. Senior Army commanders, however, strongly resisted the Kennedy administration's emphasis on developing counterinsurgency capabilities. Traditional Army doctrine persisted even after U.S. ground forces began fighting in Vietnam. Counterinsurgency remained an added duty to the regular combat mission of Army divisions and brigades. Even the Special Forces, that Army contingency regarded as most capable of meeting the challenges of counterinsurgency, were configured to train and control guerrilla forces and to conduct guerrilla warfare in support of conventional operations. 5 The problem facing the South Vietnamese government (GVN), however, was not one of waging guerrilla warfare; rather, it was one of defending against the Communist insurgency. By 1965, the Viet Cong (VC) were "annihilating ARVN battalions as a blast furnace consumes coke." 6 In order to assure the survival of the GVN, in 1965 President Lyndon Johnson granted General Westmoreland's request that 200,000 U.S. troops be deployed to South Vietnam.

It was a different historical baggage train that carried the Marine Corps into Vietnam. The traditional Corps' mission of policing Navy yards and manning the rigging of Navy fighting ships in the nineteenth century evolved into that of a colonial light infantry expeditionary force in the early twentieth century.

Historically, the Marines had been "First to Fight" because of their ability to mount small infantry strike forces on short notice. Regular Army troops had larger logistical needs, which required more expense and delay. Further, there was the feeling within the U.S. government that intervention by Marines was less provocative than the dispatch of regular Army forces. In this view, the deployment of Marines abroad was not considered tantamount to an act of war, while deployment of Army troops was. 7 As a result, in the period between World Wars I and II, the Marines acquired considerable experience in such aspects of counterinsurgency as pacification and the creation of native gendarmeries during operations in Haiti, the Dominican Republic, and especially Nicaragua.

During World War I, Marine commanders had resented attempts by the Army to use highly trained Marine forces in rear zones as support troops for the American Expeditionary Force. The Marines preferred the division of military resources employed in World War II, in which the Army concentrated its efforts in the European theater and the Marines assumed a leading role in fighting the Japanese, to that of Korea, where Marine ground and air forces were under operational control of the Army and Air Force and did not operate independently. In Vietnam, the Marines hoped to avoid the allocation of their resources in a manner subservient to other services.

In February 1965, the U.S. embarked upon a policy of sustained air strikes against North Vietnam (Operation ROLLING THUNDER). Senior Army commanders concluded that deployment of American ground forces to Vietnam was essential to provide base security for the air campaign. Upon being informed of this decision, Vietnamese commanders expressed concern about the reaction of the Vietnamese population to the presence of U.S. combat troops. Given the historical basis for the deployment of Marines abroad, it is ironic that in March, 1965, Assistant Secretary of Defense John T. McNaughton stated the desirability of deploying the Army's 173d Airborne Brigade rather than the 9th Marine Expeditionary Brigade (9th MEB): some planners felt the impact of light airborne infantry would constitute a "quieter arrival" than the formidable brigade of Marines with tanks, amphibious tractors, and other heavy weapons embarking from an sea-borne armada. General Westmoreland preferred the Marine force as being more self-sustaining. Executing a plan that had been in existence since 1959, the Marines came ashore by sea and air on March 8. 8

The Vietnam War was primarily a land war, and it was the U.S. Army that determined the operations, tactics, and most of the strategy employed in Vietnam. 9 Army theory held that the insurgency in Vietnam would be conducted in three phases. In the first phase, the Communists would proselytize among the masses; in the second, guerrilla operations would commence; the third phase would see open warfare as the now-strong insurgents sought to topple the GVN. By 1965, according to General Westmoreland, North Vietnamese Minister of Defense General Vo Nguyen Giap had moved the fighting in Vietnam to the third phase, which would necessarily be a big-unit war. The U.S. Army committed its ground forces to counter this perceived threat. The emphasis was on conventional operations. 10

The initial mission for the Marine force was limited in scope. The JCS landing order directed that the Marines would not engage Viet Cong in combat. Marines would only defend the Da Nang airfield. 11 The JCS favored an enclave strategy whereby the U.S. would increase its logistic capabilities to allow for the absorption of additional American combat forces. Westmoreland, still displaying concerns over the vulnerability of base areas to enemy action, suggested the deployment of additional Marine forces to guard the Army communications installation at Phu Bai, north of the enclave at Da Nang. This recommendation was supported by the JCS. Differences between the Marine Corps and the U.S. Army-led Military Assistance Command, Vietnam (MACV) date from this period.

Victor H. Krulak, Commanding General of the Fleet Marine Force, Pacific, and former Special Assistant for Counterinsurgency for the JCS, felt that Phu Bai was tactically indefensible. Krulak was cognizant of the numerical limitations of Marine forces in Vietnam and felt the Army facility should be moved to another place. This would allow Marine forces to remain concentrated in areas where they would be more productive. Army wishes prevailed, and in April 1965, two Marine battalions were deployed to establish an additional enclave at Phu Bai.

Leaders in Washington were convinced the situation in Vietnam had continued to deteriorate. Additional U.S. troops arrived in Vietnam, the Viet Cong achieved major victories in May and June, and the relatively low-risk enclave strategy was discarded. According to the Pentagon Papers, Westmoreland and the JCS articulated the strategy of search and destroy in keeping with sound military principles garnered by men accustomed to winning. The foundation of this strategy was to take the war to the enemy and deal him the heaviest possible blows. 12 Combat restrictions placed on the Marine force were removed. The new mission included offensive operations to find and destroy the VC in the general Da Nang area. Although initial contacts with the VC were light, Department of Defense officials felt this situation was only the lull before the oncoming storm. In this view, large enemy units remained the major threat to South Vietnam. Marines established another base south of Da Nang at Chu Lai. The 9th MEB became the III Marine Amphibious Force (III MAF), with Major General Lewis Walt commanding.

Senior Marine commanders placed less emphasis on search and destroy operations than did Army commanders because the Marines viewed large units of enemy forces as the secondary threat to the security of South Vietnam. General Walt, shortly after taking command, noted that 150,000 Vietnamese civilians were living within mortar range of the Da Nang airfield. Walt conveyed to the JCS his conviction that the real target in Vietnam should not be the Viet Cong or North Vietnamese Army (NVA) but the Vietnamese people. 13 Only with the support of the civilian population could the enemy operate in sufficiently close proximity to Da Nang to cause damage to U.S. facilities. By winning over the allegiance of the Vietnamese to the GVN, base security would be accomplished. Large enemy formations posed no threat if they could not operate in populated areas.

Retired Marine general Edward H. Forney, then Public Safety Advisor with the U.S. Operations Mission in Saigon, felt the historical experiences of the Marine Corps in Haiti, the Dominican Republic, and Nicaragua had particular relevance to the insurgency in Vietnam. Forney said the Marines should link their pacification efforts with Vietnamese militia at the local village and hamlet level in order to provide the sort of operation around which the people of Vietnam would rally. According to Forney, lack of emphasis on this type of pacification was the major deficiency in operations then being conducted in Vietnam. 14

Westmoreland felt the Marines were wrong. In June 1965, MACV requested that a total of forty-four allied battalions be committed to Vietnam. If South Vietnam were to survive, the U.S. had to have a hard-hitting offensive capability on the ground. Westmoreland wanted to forget about enclaves and take the war to the enemy with allied troops that could be maneuvered freely. 15 General Krulak observed that the Marines never felt the war stood to be won by grand maneuvers of large forces "in the Tannenberg or Chancellorsville image," but rather in the villages and hamlets. 16 Army General Harry Kinnard, commander of the 1st Air Cavalry, felt the Marines did not know how to fight on land and were reluctant to do so. General William Depuy of the MACV staff felt the Marines ". . . came in and just sat down and didn't do anything." 17 Different philosophies regarding the appropriate emphasis on pacification versus search and destroy operations would remain at the heart of the disagreements between the Army and the Marine Corps in Vietnam.

Krulak felt there was no virtue in seeking out large units of NVA in the mountains and jungles of Vietnam; as long as they stayed away from populated areas they posed no threat to anyone. By destroying the guerrilla fabric among the people, the U.S. would deny the enemy the logistic bases necessary for continued operations against the GVN. The U.S. should only fight large enemy units when they posed a particular threat to the populated areas. 18 Westmoreland had a different perception. Intelligence reports in February 1966, indicated that two NVA divisions had infiltrated across the Demilitarized Zone (DMZ) into the two northernmost provinces of South Vietnam. The MACV commander felt the intention of the NVA was to seize Quang Tri and Thua Thien provinces and the important city of Hue to use as bargaining points in future negotiations. 19

The Marines resisted every effort to extend their forces northward, preferring to concentrate efforts on pacification in the more densely populated south. In April 1966, at the insistence of General Westmoreland, the Marines began reconnaissance operations near Khe Sanh in the northwestern corner of Quang Tri province. Initial sightings of enemy troops caused the deployment of additional Marine reconnaissance elements in the DMZ area. By July 1966, heavy fighting occurred in the DMZ region between regular NVA and Marine units. Bases were established at Dong Ha, Cam Lo, and the Rockpile. Westmoreland became alarmed at the extent of the fighting in the north. Fearful that large NVA units would bypass the Marine defenses in the Dong Ha-Rockpile central DMZ area and enter South Vietnam from the northwest, Westmoreland suggested the Marines reinforce Khe Sanh.

The Marine command also resisted Westmoreland's suggestion regarding Khe Sanh. The assistant commander of the 3d Marine Division, General Lowell English, claimed that Khe Sanh had no tactical value; if it were lost, it would make no difference. In the Marine view, Khe Sanh was too isolated and would be too hard to support. Bowing to the inevitable, the Marines agreed to reinforce the base in order to retain the prestige of doing it on their own rather than being forced to do so. 20 MACV was convinced the NVA were planning a massive advance into Quang Tri province. The 3d Marine Division was ordered north from Da Nang to meet this threat. Army troops moved to Da Nang to replace the departing Marines. The expected enemy offensive along the DMZ did not materialize. Nevertheless a sizeable Marine presence would remain in the north, seriously hampering the Marine pacification program in the southern sector of their Tactical Area of Responsibility (TAOR). General English summed up the Marines' frustration in Vietnam at the end of 1966 by noting the Corps had been assigned too much real estate and not enough troops. Generals Krulak and Walt thought the Communist leaders wanted to draw the Marines out of the populated I Corps coastal area into a campaign of attrition in the underpopulated areas of northern Quang Tri province. 21 Since attrition was central to Westmoreland's strategy of search and destroy, the objectives of the Communists and MACV were such that continued fighting between the Marines and NVA along the DMZ was bound to occur.

By 1966, it became evident that Operation ROLLING THUNDER had proven ineffective in stopping the infiltration of men and supplies into South Vietnam from the north. In the search for a better way to stop this infiltration, the Department of Defense proposed the construction of a barrier across the DMZ and Laotian panhandle. In October 1966, Westmoreland ordered his subordinate commands to study the barrier concept as developed by the MACV staff. The Seventh Air Force developed an aerial barrier in Laos, while III MAF and MACV planned for a conventional barrier along the DMZ. III MAF commander General Walt ordered 3d Marine Division commander General Wood Kyle to design the Marine component of the barrier. Both Marine generals expressed strong reservations about the barrier concept, and Marine Corps opposition to it remained consistent. In their view, the barrier concept was fantastic, absolutely impractical, and would tie down additional troops that could be more effectively deployed in other ways. 22 Neither Walt nor Kyle had any choice in the matter, and MACV ordered the Marines to construct the barrier.

In the fall of 1967, MACV received intelligence reports of massive NVA troop buildups in the vicinity of Khe Sanh. General Phillip Davidson, the MACV intelligence chief, felt General Giap intended to overwhelm the base in order to force an end to the war in Vietnam. 23 General Westmoreland was convinced that the Marines underappreciated the severity of the enemy threat to Khe Sanh. Feeling Marine assets were inadequate to the task, Westmoreland ordered U.S. Army troops into I Corps to reinforce the Marines. I Corps had been predominantly a Marine preserve since 1965. In the view of MACV, the Marines had lost the initiative against the NVA; Westmoreland began to consider putting the Army in charge of I Corps. 24

The Marines suffered heavy casualties in 1967 during heavy fighting with the NVA at Con Thien along the DMZ. During this battle, the Marines asked the Air Force for tactical support. After the fighting, the Marines were bitter in their assessment of the assistance provided by the Air Force. Marine General John Chaisson, chief of the MACV operations center, told Air Force General William Momyer he had no doubt in his mind that the Air Force had put insufficient emphasis and effort into assisting the Marines at Con Thien. Months later, while preparing for the defense of Khe Sanh, General Westmoreland asked III MAF commander General Cushman to release control of Marine tactical aircraft that were not actually supporting Marines in combat. Cushman, remembering Con Thien, bristled at the suggestion. 25

Marine forces were outfitted with fewer artillery pieces than Army units. In theory, Marines got gunfire support from Navy ships. When operating beyond the range of naval gunfire, Marines relied on the tactical air support of Marine pilots who had earlier trained as infantrymen. It was this special relationship between comrades that Cushman opposed severing. The disagreement over control of tactical air assets reached into the highest levels of the U.S. military establishment. III MAF seemed to be in virtual revolt over the matter. The Army felt the Marines had more available tactical support than they needed and should be willing to share it with Army forces. Westmoreland was unwilling to budge on this controversy - indeed, he felt so strongly about this that he claimed it was the one issue during his Vietnam service that prompted him to consider resigning. Eventually the Marines were forced to accept Westmoreland's concept for a single air manager. 26

The war dragged on in the face of these disharmonies between the Army and Marine Corps. American civilian leaders remained concerned with managing the bombing campaign against North Vietnam. As long as MACV restricted military operations to South Vietnam, the Army continued to play the lead role in deciding the best way to wage war. General Westmoreland explicitly rejected the Marine policy of paying less attention to large units of enemy troops, while favoring small unit activities to accomplish pacification. 27

The Marines in I Corps fought two wars: one of counterinsurgency in the heavily populated southern portion of their TAOR, and a more conventional war, at MACV insistence, against large NVA formations in the north. By being forced to fight two wars, the Marines felt they had inadequate assets to properly wage either. MACV felt the Marines were too parochial in their outlook, that the threat of NVA forces entering Vietnam from various avenues within I Corps threatened the integrity of the entire nation of South Vietnam.

General Westmoreland remained convinced of the critical importance of Khe Sanh. The Marine combat base there remained garrisoned as long as Westmoreland was the MACV commander. In April 1968, the Army 1st Cavalry Division (Airmobile) was assigned the lead role in the operation to establish overland communications with the Marines at Khe Sanh. MACV felt Army high-mobility tactics would be more effective against NVA forces in northern I Corps than anything the Marines could offer. On 1 July 1968, General Creighton Abrams replaced Westmoreland as MACV commander. The Khe Sanh Combat Base was immediately shut down and abandoned.

Marine and Army tactics began to converge. General Abrams was willing to place more emphasis on pacification and lead Army operations away from their previous conventional orientation. The reversion by the enemy to a lower-level insurgency after the losses suffered during Tet, 1968, inclined the Americans to respond with smaller unit activities. MACV was coming to the realization that large-scale U.S. combat operations had brought little in the way of over-all security to the countryside of South Vietnam. The attrition of enemy forces remained the primary goal of American forces, however.

Tactics employed by the Marines also changed. In May 1968, Major General Raymond Davis assumed command of the 3d Marine Division. Davis ordered the division to forego its earlier reliance on fixed defensive positions. In the latter half of 1968, the Marines received additional helicopter assets with the arrival in large numbers of the CH-46 medium transport helicopters. Davis also secured the promise of Army helicopter support from Army General William Rosson, Provisional Corps commander, and from General Richard Stillwell, Rosson's successor at XXIV Corps. With this helicopter support, the Marines moved out of their positions south of the DMZ and began Army-style mobile operations in western Quang Tri province.

It was domestic political considerations, and not successes on the battlefield, that offered impetus to the American decision to begin withdrawing its combat forces from Vietnam. General Abrams believed that an American military victory was impossible considering the restrictions under which they were compelled to operate. 28 U.S. Defense Secretary Melvin Laird was determined to effect a major change in American policy toward the war in Vietnam. Despite the unanimous view of the major U.S. agencies involved in the war that the policy of Vietnamization would be unable to deal with the threat posed by the Vietnamese Communists, the new administration of President Nixon instructed MACV to develop plans for turning the war over to the Vietnamese armed force.

When it came time for the first pullout of U.S. forces in July 1969, General Abrams favored the departure of the 3d Marine Division. General Westmoreland, still convinced of the threat posed by NVA forces in the northern provinces, interceded to keep the Marines in I Corps. 29 Abrams later agreed that the first U.S. troops removed from Vietnam would be a combination of 3d Marine Division and Army 9th Infantry Division units. Departing Marine units were not directly replaced. As the Marines pulled out of their positions in the north, the bases were offered to the Army. This offer was rejected.

Marine strength in I Corps at the beginning of 1969 was 81,000, with 50,000 Army troops under III MAF command. By the end of the year Marine strength had fallen to 55,000 men as Army forces replaced the Marines. In 1970, III MAF relinquished control of I Corps to the Army XXIV Corps. 30 Defense of the northernmost provinces was no longer the responsibility of the Marine Corps.

At the beginning of large U.S. troop deployments to Vietnam, the various services were eager to participate. The Army wanted to regain influence lost to the Air Force and naval air that had dominated the strategy of massive retaliation dominant in the early years of the Cold War. Matters of service prestige and career enhancement were at stake in Vietnam. During the advisory period, Marine commanders were concerned that the Corps was only moderately involved in the conflict, which was contrary to Marine Corps tradition. The Marines had no special counterinsurgency units such as Army Special Forces. The only solution to this problem was for the Marines to commit regular Fleet Marine Force units on a large scale.

The Marine command in I Corps would have preferred a free hand in waging war, free of Army supervision. Vietnam was the longest, and in many ways, the most difficult war for the Marines - Marine casualties in Vietnam exceeded those of World War II. By the time U.S. forces began redeployments in 1969, it was clear that Vietnam was more a place for the military services to lose prestige rather than gain it. The MACV initial plan to redeploy the 3d Marine Division only included ground units. The Marines, still opposed to the breakup of the their air-ground team, favored the removal of both fixed-wing and rotary air assets along with the ground units of the 3d Marine Division. Marine Commandant General Leonard Chapman noted that although these air assets were not organic to the Marine division, they were essential if the division was to be used as a strategic reserve in the Pacific. The Corps was looking beyond Vietnam, seeking the re-creation of its force deployment that existed prior to participating in this unsatisfactory war.

Army doctrine was a major contributor to the determination of Army tactics in Vietnam. General Westmoreland claimed to understand the historical rationale behind the employment of Marine Corps doctrine in Vietnam. He understood that the Marines were employed in Vietnam on operations contrary to their mission simply because they existed and were available in time of need. While allowing that Marine doctrine neither trained nor equipped them for sustained operations ashore, such was the manner in which they were deployed by MACV in Vietnam. Given the inability of the Army to operate in a manner contrary to their own historical experiences, it seems simplistic for Westmoreland to fault the Marine Corps for an over-rigid adherence to its own doctrine. 31