“Despite the eventual outcome of the war, the Marines had demonstrated that counterinsurgency can be used successfully to achieve operational-level goals.”

Dr. David Strachan-Morris, SFHEA

IN THE CONTEXT of U.S. involvement in the Vietnam War, concepts such as success or failure and victory or defeat are still hotly contested.

And although the war did not end well for the United States, there were still some success stories. The U.S. Marines provides one of them.

The Corps’ primary mission was to defend three bases along the coast of the northern provinces of South Vietnam. And their decision to employ counterinsurgency to provide defence-in-depth around theses bases meant they were successfully able to achieve that mission and, at the same time, demonstrate the utility of counterinsurgency as an operational level tool.

The U.S. Marines deployed the 9th Marine Expeditionary Brigade to Vietnam in March 1965 following a series of attacks on American military bases. The primary mission of the brigade, which soon expanded to a division, was to defend three bases in the northern provinces of the Republic of Vietnam, at Phu Bai, Da Nang, and Chu Lai. This remained their primary mission throughout the period 1965 to 1968, although their wider remit changed from a mainly defensive role to one that included offensive action against the North Vietnamese Army and Viet Cong (hereafter NVA/VC).

Even after the U.S. Marine presence expanded to a second division, becoming III Marine Amphibious Force (III MAF), the task of defending those three coastal bases was listed first in every Letter of Instruction (LOI) issued by the Commander of U.S. Forces in Vietnam, General William Westmoreland. This point is acknowledged in the histories of the Marines in Vietnam but its importance in terms of operational planning and decision making has been overlooked. What is seen by many as a dogmatic adherence to counterinsurgency was in fact a sound operational decision by the Marines that led to eventual success in achieving their main mission.

The decision by the first Marine commander in Vietnam, Lt. Gen. Lewis W. Walt, to emphasise counterinsurgency over ‘conventional’ attritional warfare against the NVA/VC is often assumed to reflect an institutional stance by the Marines that Vietnam was a “people’s war” and that counterinsurgency was the right strategy. In fact, Walt was agnostic on an approach to the war when he arrived in Vietnam; his eventual decision to adopt a counterinsurgency approach was dictated by the situation on the ground and was based on three key factors: his specific mission; his force structure and logistics; and the institutional knowledge and expertise of the Marine Corps itself.

The requirement to defend three fixed locations in heavily populated coastal areas would always be a considerable drain on resources; even more so as these bases became crucial logistical hubs to support the war further inland. What General Westmoreland and his subordinates characterised as a stubborn unwillingness on the part of the Marines to move inland from the coasts can also be interpreted as a reluctance to lose focus on a key task and risk losing crucial assets.

The apparent reluctance to move too far inland becomes even more understandable when considering the force structure and logistic capability of the Marine Corps at the time. It’s often said “amateurs talk strategy but professionals talk logistics” and, despite being a somewhat oversimplified truism, this was the case with the Marines. The 1956 Hogaboom Board (or the Fleet Marine Force Composition and Organisation Board, to give its proper title) removed much of the heavy artillery and logistical movement capability from the Fleet Marine Force (the main fighting component of the USMC), leaving the Marines as essentially rapid-deployment light infantry that was heavily reliant on carrier-borne air power and offshore naval artillery support. While the U.S. Army benefitted from a rapid increase in helicopter airlift capability, the Corps lost much of its transportation and became reliant on jeeps and light trucks to move its troops and equipment. The initial deployment of the 9th MEB taxed the Marines’ logistic system almost to the breaking point.

The final factor in determining the Marine Corps’ operational approach was institutional knowledge and expertise. The USMC had considerable experience in counterinsurgency and pacification gained during the ‘Small Wars era’ of the 1920s and 1930s. This experience had been distilled into the Small Wars Manual in 1940. Although Walt and his contemporaries in senor positions in the Marine Corps had not fought in those wars themselves, they had been taught by those who had and those lessons had stayed with them. The younger generation of Marine officers were well versed in the works of insurgents, such as Mao Tse Tung, and counterinsurgents, including the British expert Robert Thompson and the French expert David Galula. When the Marines were faced with the task of defending bases in populated areas it seemed only natural to use pacification and counterinsurgency techniques, including building up local militias, as a means of achieving defence in depth.

An emphasis on counterinsurgency was a logical choice at operational level; it was the appropriate tool to achieve a specific aim within a specific area for a specific length of time. Critics quite rightly argue that it was not necessarily the right approach to win the war itself and that the war was too complex for one single approach to work. And although they were making a contribution to the war effort, the Marines were not there to win the war by themselves – they were there to do a particular job.

One of the aims of the Marines was to create pacified “ink blots” around their bases and gradually expand these until they covered the whole of the populated coastal region within their area of operations. This strategy was based on counterinsurgency theory at the time, which did make claims to be war-winning. But when the North Vietnamese launched the Tet Offensive in early 1968 they were unable to overrun the three bases and the effective counterinsurgency campaign was a major factor in the failure of what was to have been a general uprising by the population against the South Vietnamese Government and the U.S. forces in the northern provinces. By the end of the Tet Offensive, the Marines had been vindicated in their choice to emphasise counterinsurgency at an operational level and had successfully achieved their main mission.

The war in the Marines’ area of operation changed after 1968. The election of President Nixon at the end of that year led to the start of the withdrawal of U.S. forces and the USMC reduced its presence until only the base at Da Nang remained. By 1972 the Marines were gone. Counterinsurgency became more of a focus at strategic level but control passed to an organisation called CORDS (Civil Operations and Revolutionary Development) led by a senior officer in Saigon, who coordinated the civil and military counterinsurgency efforts. In a way this too was a Marine success as CORDs replicated on a larger scale the processes and structures the Marines had established in their area of operations. Despite the eventual outcome of the war, the Marines had demonstrated that counterinsurgency can be used successfully to achieve operational-level goals.

David Strachan-Morris the author of Spreading Ink Blots from Da Nang to the DMZ: The Origins and Implementation of the US Marine Corps Counterinsurgency Strategy in Vietnam March 1965 to November 1968, (Helion & Company Ltd, 2020).  A lecturer in Intelligence and Security in the School of History, Politics and International Relations (HYPIR) at the University of Leicester, Strachan-Morris previously worked as a political and security risk analyst in the private sector and served in the British Army. He holds a Ph.D from the University of Wolverhampton, having written his thesis on the U.S. Marine Corps in Vietnam.