A Winning Strategy: What Could Have Been

By Col. Andrew R. Finlayson, USMC (Ret.)*

“Amateurs talk about tactics; professionals talk about logistics.”

An old military proverb

Why did the Vietnam War end as it did? For the past 49 years I have examined every reason put forth by a host of writers, carefully examining their arguments, discussing these arguments with other military analysts and veterans, and revising my findings in the light of my own experience in South Vietnam. From North Vietnamese military officers and former VC political cadres to international journalists, military historians and U. S. and ARVN veterans of the war, I have researched the reasons they have given for the root causes for the defeat of the United States and our ally, the Republic of Vietnam. While there were many components to our failure to secure the sovereignty of South Vietnam, I have concluded that the principal and ultimate cause was a fatally flawed strategy, one based upon wishful thinking, hubris, and incorrect assumptions. Despite having the necessary information needed to formulate a winning strategy, our national leaders and military planners failed to use this information to formulate and execute a winning strategy.

Unfortunately, the North Vietnamese had a far greater appreciation for these factors than our own leaders, which resulted in the communists forging a far more effective strategy for the achievement of their goals—and to do so despite some extremely burdensome and potentially lethal constraints.

For the North Vietnamese the goal they set for themselves - and one they never abandoned or modified - was the complete unification of Vietnam and the domination of the Indo-China peninsula, to include Laos and Cambodia (Turner, Robert F, Vietnamese Communism: Its Origins and Development, Stanford: Hoover Institution Press 1974, pp. 18-19, 78-79). In order to achieve this, the North Vietnamese communists used the template they learned from the lessons of the Chinese Civil War when the Chinese Nationalists were defeated by the Chinese Peoples’ Liberation Army (PLA) in 1949 and the Viet Minh used during the First Indochina War against the French. They capitalized on this Chinese strategy and adopted it to their own strategic aims. This strategy was dependent upon organizing the rural population under communist leadership, forming a united front under communist leadership, obtaining economic and military resources from communist patron nations, securing North Vietnam from external attack by establishing a modern, conventional army, maintaining a pervasive internal security apparatus, and establishing bases and sanctuaries on the border with South Vietnam so as to resupply and reinforce their forces operating inside South Vietnam.

Central to their aim for conquering South Vietnam was the necessity to keep the flow of men and arms from North Vietnam to South Vietnam constant and unimpeded. They accomplished this by establishing a logistics system in 1959 that allowed them to move Soviet and Chinese arms and ammunition, and North Vietnamese Army units from North Vietnam through Laos and Cambodia to base camps and storage areas along the western border of South Vietnam. The North Vietnamese knew that this logistical system was essential to the success of their strategy since it allowed them to modulate the level of violence inside South Vietnam and to maintain a constant pressure on American and GVN forces. Since the Americans pursued a strategy of attrition the North Vietnamese knew this American strategy would only work if the Americans were able to prevent the North Vietnamese from reinforcing and resupplying their forces in South Vietnam. This system, which the Americans called the Ho Chi Minh Trail and the North Vietnamese called the Truong Son Trail, consisted of a 9,940-mile infrastructure of mountain trails, roads, and waterways in eastern Laos and Cambodia. Keeping the Ho Chi Minh Trail open was considered by the North Vietnamese to be the “linch pin” for their ability to wage a successful war inside South Vietnam and defeating the attrition-based strategy of the Americans (Nguyen, Lien-Hang T. Hanoi’s War: An International History of the War for Peace in Vietnam, UNC Press, 2012, p.201). In essence, they saw their logistics system as the key determinant in defeating the attrition-based strategy of the Americans.

The Ho Chi Minh Trail had some serious vulnerabilities, which were recognized by the Americans, but the methods used by the Americans to take advantage of these vulnerabilities were largely ineffective and did not prevent the flow of men and arms south. The Americans relied on air power and CIA-directed indigenous guerrilla forces to stem the flow of North Vietnamese Army units and military supplies moving along the trail; however, both of these efforts proved to be unsuccessful. This reliance on airpower and covert guerrilla forces was an attempt to maintain the fiction that Laos and Cambodia were neutral countries.

The key vulnerabilities of the Ho Chi Minh Trail were geographical in nature. Since seventy percent of the military supplies entered North Vietnam via the sea through Haiphong harbor, and to a lesser extent the harbor at Vinh, these ports were vulnerable to mining by the Americans, but this was not accomplished until the end of the American participation in the war and was reversed as part of the negotiated peace agreement of 1973. Another vulnerability was the mountain passes that led from North Vietnam into Laos at the northern entry point to the trail. The primary pass used by the North Vietnamese was the Mu Gia Pass, but they also used three other passes to a lesser degree. These passes were the Ban Ragivne Pass, the Ban Karai Pass, and the Neo Neua Pass.

However, the most significant vulnerability of the Ho Chi Minh Trail was the geography in the Panhandle of Laos where the trail system converged at two choke points: a 10-mile radius centered on Tchepone and an area around what was known as the “Four Corners,” several miles south of Tchepone. All of the men and supplies moving south had to move through these two choke points. Whoever controlled these choke points controlled the flow of men and material south.

Given these vulnerabilities, was there a better strategy that the Americans could have pursued that would have prevented the flow of men and arms to South Vietnam? The only plausible answer to the question is the one that General Westmoreland and his staff came to in 1965 when they began to plan for the occupation of the Panhandle of Laos. Instead of relying on air power and indigenous special operations teams, which failed to stem the flow of troops and equipment to South Vietnam through Laos, General Westmoreland planned to use U.S. ground troops to block and hold the terrain between Dong Ha in South Vietnam and Savannakhet on the Mekong River in Laos. This obvious plan, which was studied as early as 1964, was delayed initially by the U.S. State Department which did not want to threaten the neutrality of Laos or give up their primary role for management of American affairs in that country. Later the implementation of the plan was thwarted by the State Department and the CIA, both of whom did not want to give up their control of conducting the “Secret War” in Laos. Even the U.S. military was not uniformly in favor of the plan, citing that it was logistically risky or the North Vietnamese would simply go farther west to get around it (Collins, John M., “Going to Tchepone: Oplan El Paso,” Joint Forces Quarterly, Autumn/Winter 1997-98, pp.128-129; Also see Harris, J. P., Vietnam’s High Ground: Armed Struggle for the Central Highlands, 1954-1965, Lawrence, KS, University Press of Kansas, p. 340.)

An Alternate Strategy

Of all the possible strategies proposed for an American victory in Vietnam, the strategy of cutting the Ho Chi Minh Trail on the ground in southern Laos, using US ground forces, offered the best chance for success. The following reasons pertain:

First, the use of U.S. ground troops along the Dong Ha-Savannakhet axis would physically cut the Ho Chi Minh Trail, making it impossible for North Vietnamese troops and equipment to move into South Vietnam in the numbers needed for support conventional military operations. Geography favored the US since the Ho Chi Minh Trail had to pass through two “choke points” in Laos that were easily defended. All of the trails and roads built by the North Vietnamese in Laos came together within a ten-mile corridor at Tchepone and again farther south in the “Four Corners” area near the village of Muong Nong. By choking off the Ho Chi Minh Trail in Laos, U.S. and ARVN forces would no longer need to protect a border with North Vietnam, Laos and Cambodia that stretched for nearly 1400 miles. They would be able to concentrate their forces along a frontage of only 225 miles, the distance from the East China Sea to the Mekong River. In order for North Vietnamese supply columns to move south, the North Vietnamese would need to breach this barrier using large numbers of conventional forces fighting in terrain that heavily favors the defense. Even if they broke free, they would have to maintain the breach continuously or face isolation of their forces moving south through mountainous terrain. If, as some unsophisticated commentators have asserted, the North Vietnamese were able to redirect the Ho Chi Minh Trail further west into Thailand to avoid the barrier, they would be forced to extend the trail across the Mekong River, a significant physical obstacle easily covered by U.S. air and riverine forces and screened by a force like the US First Air Cavalry Division, using bases on the Thai side of the river. Since the bulk of supplies sent south by Unit 559 came by truck, the Mekong River posed an almost impossible logistical obstacle for them since they would not be able to bridge it or move their trucks across it using boats without being easily detected. Also, moving the trail across the Mekong River would mean they would be transiting the sovereign country of Thailand, a SEATO ally of the United States. Such a move into Thailand, which was not a “neutral” country like Laos, would certainly destroy any claim by the North Vietnamese that they were not sending troops to South Vietnam. What’s more, if the North Vietnamese were able to move their troops and supplies across the Mekong River into Thailand, they would be confronted with a hostile population in a country that did not have the communist infrastructure needed to create a system of bases and sanctuaries, not to mention adding nearly 500 more miles to their trip south. A further complication for the North Vietnamese would be the terrain in Thailand. Unlike the terrain in eastern Laos, which is mountainous and jungle clad, the terrain the North Vietnamese would have to transit in Thailand is flat and open, making it relatively easy to detect their movement and expose them to attack. Furthermore, any North Vietnamese units that were able to get to the Mekong River would have to abandon their vehicles on the Laos side, and they would not be able to maintain any petroleum pipelines once they were in Thailand. It is difficult to imagine how the North Vietnamese would be able to maintain their infiltration figures of 8,000 men per month and 5,000 tons of equipment and ammunition per month just to make up for their losses in South Vietnam if U.S. forces were occupying defensive positions from Dong Ha to Savannakhet.

To gain some perspective on the logistical challenge to the North Vietnamese, consider the statistics provided by them in their official history of the war. They were using 5,372 trucks on over 3,959 kilometers of vehicle-capable roads in Laos in 1967 to send a total of 61,000 tons of supplies to South Vietnam that year (Victory in Vietnam, p. 208). By 1969, the North Vietnamese were sending 170,000 tons to South Vietnam per year via truck along the Ho Chi Minh Trail Road system (Victory in Vietnam, page 243). In 1970, the Group 559 reported that the US Air Force had destroyed 2,432 of their trucks on the trail during the dry season in Laos (Victory in Vietnam, p 262). In 1974, the second year of the Paris peace accords and the year before the final communist offensive, the North Vietnamese had built over 400 miles of new hard surface roads in Laos and installed two petroleum pipelines, which allowed them to move a substantial number of tank, artillery, and mobile air defense systems into South Vietnam (Losing Vietnam, p. 168). It is simply inconceivable that infiltration levels like those reported by the North Vietnamese for the years 1966 to 1974 could have been maintained if the road systems in Laos were physically blocked.

Second, the force levels needed to defend the Dong Ha-Savannakhet axis would have been less than those that were employed by the U.S. pursuing their attrition-based strategy in South Vietnam. By 1969, the U.S. employed eleven division equivalents in South Vietnam with over 500,000 troops. The plan to establish the Dong Ha-Savannakhet defensive barrier would require only two U.S. Marine divisions in Quang Tri Province, South Vietnam, and four U.S. Army divisions in southern Laos, with an additional U.S. Army division positioned in the vicinity of either Paksane, Laos or Nakhon Phanom, Thailand where it could screen the Mekong River north of Savannakhet and threaten the right flank of any North Vietnamese force moving against the barrier to the south. As a SEATO ally, Thailand could be called upon to employ their military and border police units along the Mekong River and in depth along any potential infiltration routes the North Vietnamese might try to establish in Thailand. The large brown water fleet of the US Navy could also be employed to screen the Mekong River north of Savannakhet and provide security for allied logistical use of the river. South Vietnamese units, such as the Rangers and the elite 1^st Division could serve as a second line of defense for the barrier and could be used to hunt down any NVA units that penetrated the barrier. Such an alignment of forces would require the North Vietnamese to fight a conventional battle against American, South Vietnamese, and Thai force that enjoyed a considerable advantage in terms of fire power, mobility, logistics, and terrain.

Third, by concentrating the U.S. military ground forces in only one province of South Vietnam and the Panhandle of southern Laos, the bulk of the South Vietnamese forces could be devoted to dealing with the VC military units and the VCI in the remaining 43 provinces of South Vietnam, thus allowing them to concentrate on pacification and nation building, two tasks better suited to indigenous forces. In addition to using both the U.S. and ARVN forces in a more appropriate manner, it would effectively remove the presence of American forces from the South Vietnamese countryside where their presence often took on the appearance of an occupying army. It would also end the sometimes-profligate use of American supporting arms in the populated areas of South Vietnam and concentrate that immense destructive firepower against the North Vietnamese Army inside North Vietnam and southern Laos. By reducing South Vietnamese civilian casualties from American supporting arms and employing American ground forces in the largely sparsely inhabited regions of southern Laos and the DMZ of South Vietnam, a far more humane and moral military strategy would be employed.

Fourth, while logistically challenging, the Dong Ha-Savannakhet defensive barrier was far easier to establish and maintain than its detractors claimed at the time, and some still claim today. The port of Danang in northern I Corps could easily support two U.S. Marine divisions while the ports of Thailand and the road system running from those ports to Savannakhet along the Thai side of the Mekong River are adequate to support five U.S. divisions, with only modest improvements. U.S. Air Force bases already existed in eastern Thailand and would only need some expansion to support the U.S. forces in Laos, and the C-130 capable Laotian airfields at Ban Houei Sane and Tchepone and a C-23 capable airfield at Muong Nong could be made operational by military engineers in two weeks’ time (Collins, p.123). The argument made by military planners on the Joint Chiefs of Staff for the need to activate the US reserves to support the engineering requirements for the barrier does not stand up to scrutiny. Private U.S. and other Western engineering contractors, already active in both Thailand and South Vietnam using local labor, could have handled this requirement easily without the political cost to the U.S. incurred by calling up reserve military engineer units. If the North Vietnamese could build and maintain roads under the pressure of constant bombing by U.S. aircraft using coolie labor, it is safe to assume that South Vietnamese and Thai laborers could do it under the threat of North Vietnamese attack. Using local labor to build roads and defensive positions would be cheaper than using U.S. military engineers and would help the local rural economies by providing a large number of local people with better wages than they would have received tilling the land. Such road building and maintenance jobs would also reduce the demand for farmland redistribution, a key communist propaganda theme.

Finally, with the U.S. strategy of fighting the North Vietnamese along the DMZ in South Vietnam and in the Panhandle of southern Laos, U.S. aircraft and U.S. airfields would no longer be spread throughout South Vietnam and vulnerable to attack. Instead, U.S. air power could be concentrated at just a few airfields in South Vietnam, such as the ones at Danang, Chu Lai and Phu Bai, with the bulk of US aircraft stationed in eastern Thailand or at sea on U.S. Navy aircraft carriers, thus obviating the need to divert so many US infantry units to protecting airfields in South Vietnam.

Some Western critics of the “barrier defense” explained above, point to the failure of the “McNamara Line” electronic surveillance system in southern Laos to stem the flow of men and supplies from North Vietnam. These critics point out, quite correctly, that the North Vietnamese were able to adapt to the system of electronic intrusion devices used to monitor foot and vehicle traffic along the Ho Chi Minh Trail and still move sufficient men and tonnage to support the insurgency in South Vietnam. While the electronic intrusion devices made the North Vietnamese pay a high price for their continued use of the Ho Chi Minh Trail, they did not pose a significant enough obstacle to them, and they overcame this technological system through ingenuity and perseverance. The barrier system explained above is entirely different from the electronic one devised by the Whiz Kids in the Pentagon since that system relied on technology to stem the flow of North Vietnamese troops and equipment moving down the Ho Chi Minh Trail. The barrier system proposed in this paper would be significantly different since it would be permanently manned by U.S. troops occupying strong defensive positions similar to those found along the DMZ in Korea and defended in depth with mobile forces. It would not rely on technology and air power alone to attack traffic on the Ho Chi Minh Trail, but instead would use a system of strong points manned by infantry, backed up by artillery in hardened fire support bases with mobile reaction forces and on-call, concentrated air power. It would also entail ground and aerial reconnaissance units prowling the terrain north of the barrier, providing advance warning of any enemy movement towards it and using air strikes and artillery to harass and attrite North Vietnamese formations before they reached the barrier. The efficacy of such an arrangement could be found in the defensive system that was used along the DMZ in South Vietnam from Dong Ha to Khe Sanh near the Lao border. This barrier system effectively stopped the North Vietnamese from moving men and supplies into South Vietnam through the DMZ after 1965 and forced them to use the Ho Chi Minh Trail system in eastern Laos to infiltrate into South Vietnam. Unlike the reconnaissance in force operations, such as Lam Son 719 or the Oplan El Paso raid, where the choke points along the Ho Chi Minh Trail would only be temporarily occupied by American or SRVN forces during a few months, this barrier would be permanently occupied.

Some critics accept the fact that a barrier from Dong Ha to Savannakhet would have prevented North Vietnamese infiltration into South Vietnam using a land route, and argue the North Vietnamese would only increase seaborne infiltration using the East China Sea and the port of Sihanoukville in Cambodia. The U.S. and South Vietnamese navies were able to prevent the use of the South Vietnamese coast for infiltration after 1965 and the North Vietnamese never considered this avenue a serious means of moving the quantities of men and supplies needed to sustain their military operations in South Vietnam. Most of their seaborne attempts at infiltration were quite small and met with disaster since the movement of their infiltration vessels could be easily observed using U.S. surveillance means. Bad weather often disrupted or delayed seaborne infiltration and the distances from likely landing places to the North Vietnamese bases in western South Vietnam were great and covered areas that were populated and controlled by GVN forces. For these reasons, the North Vietnamese never used any significant seaborne routes to infiltrate their units, relying almost exclusively on the Ho Chi Minh Trail for that purpose. Even if they were forced to use seaborne infiltration because the Ho Chi Minh Trail was blocked, they would constantly have to change their offload sites, storage sites, and transport system to take into account the American and GVN sea control and surveillance superiority, thus complicating their logistics system to the point of absurdity. Proof of the North Vietnamese rejection of the feasibility of seaborne infiltration can be found in the paucity of material devoted to it in their official history of the war, and then only to point out its difficulties and miniscule tonnage of supplies provided (Victory in Vietnam, pp. 97). As for the use of Sihanoukville, they did use third country shipping to deliver supplies to that port and their Hak Lee Transportation Company in Cambodia to move those supplies to their divisions in eastern Cambodia, but this route was only viable as long as Prince Sihanouk agreed to its use and it would never be capable of covertly introducing the 8,000 or more North Vietnamese troops needed each month to maintain their force levels inside South Vietnam. It was out of the question to bring over 90,000 NVA troops each year through Sihanoukville since it would be easy to verify their arrival and thus make a mockery of Prince Sihanouk’s contention that his country was truly neutral. He was sensitive to the issue of sovereignty and he had to maintain the fiction of neutrality for both international and internal political reasons. He recognized that the use of Sihanoukville for the infiltration of North Vietnamese troops would be an open and easily verifiable violation of his country’s neutrality and would give the U.S. and South Vietnam ample justification to blockade Sihanoukville or to invade his country (The author saw several classified reports from a CIA spy inside the Hak Lee Transportation Company who provided all of the company’s invoices for the transportation of supplies from North Vietnam and China to eastern Cambodia). In any event, his regime was overthrown in 1970, putting paid to any idea of using a seaborne infiltration route in Cambodia.

Perhaps the best response to the critics of the Dong Ha—Savannakhet defensive barrier can be found in the statement of Colonel Bui Tin, the North Vietnamese officer who accepted the surrender of the South Vietnamese Government in 1975 and later filled several high-level positions in the new communist Government. He was interviewed in Paris in 1995 and asked several questions about how the North Vietnamese viewed the conduct of the Vietnam War. The following statement by Bui Tin should put to rest any lingering doubts as to the efficacy of the Dong Ha—Savannakhet barrier plan:

Question: “How could the Americans have won the war?”

Bui Tin’s answer: “Cut the Ho Chi Minh trail inside Laos. If Johnson had granted Westmoreland’s requests to enter Laos and block the Ho Chi Minh Trail, Hanoi could not win the war.” (Young, Stephen, “How North Vietnam Won the War,” Wall Street Journal, August 3, 1995, p. A8.)

From the very beginning of the U.S. involvement in South Vietnam, the evidence was readily available to justify an invasion and occupation of the panhandle of Laos. The U.S. had the experience, engineering expertise, construction assets, logistical competence, and military forces needed to conduct such an invasion, but the U.S. Government decided against it until it was too late. Because the Americans failed to deal with this essential and vulnerable aspect of the North Vietnamese strategy, they allowed the North Vietnamese to continue to send men and supplies south and to maintain sanctuaries inside Laos and Cambodia, thus allowing the North Vietnamese to modulate the level of violence inside South Vietnam while minimizing their own losses. Without the Ho Chi Minh Trail, the North Vietnamese would never have been able to execute the third phase of their revolutionary war strategy, that of mobile warfare using conventional units and tactics. In sum, the American failure to permanently cut the Ho Chi Minh Trail on the ground was the key to their failure to win the war.

*Col. Finlayson spent 32 months in South Vietnam during the Vietnam War (1967-70), working entirely in combat billets (long-range ground reconnaissance, infantry, and special operations) in four provinces and two different geographic areas of that country (I Corps and III Corps). He was also a national-level war planner during two subsequent tours of duty in the US and South Korea. As an operations analyst at US Marine Corps Headquarters (1970-72) and as an operations specialist with the Combined Forces Command in South Korea (1981-83), he worked on many of America’s war plans. He possesses three master’s degrees: MS Management Engineering, MA Asian Studies (Chinese), and MS National Strategy and Defense Economics. He is also the author of two books on the Vietnam War and several articles, studies and monographs dealing with the war.