The Combined Action Program: Vietnam Captain Keith F. Kopets, U.S. Marine Corps “Of all our innovations in Viet- rines for security. enough to defend that amount of nam none was as successful, as CAP’s Origins territory. The local population lived lasting in effect, or as useful for CAP came naturally for the in six villages, each nominally de- the future as the Combined Ac- Marine Corps because counter- fended by a militia platoon. Taylor tion Program [CAP],” wrote U.S. guerrilla warfare was already part and his officers brainstormed ideas Marine Corps (USMC) Lieutenant of the USMC heritage. From 1915 of how to improve the battalion’s General (LTG) Lewis Walt in his defensive posture. They looked to 1 to 1934, the Corps had a wealth of memoirs. British counterinsurgen- experience in foreign interventions a previously unused resource—the cy expert Sir Robert Thompson said fighting guerrillas in Nicaragua, militia platoons. CAP was “the best idea I have seen Taylor’s executive officer, Major 2 Haiti, and Santo Domingo. For ex- in Vietnam.” ample, the Marines organized and Cullen C. Zimmerman drafted a The program, undertaken by the trained the Gendarmerie d’Haiti and plan to incorporate the militia pla- USMC during the Vietnam war, the Nacional Dominicana in Haiti toons into the battalion’s defense. was an innovative and unique ap- and Santo Domingo from 1915 to He proposed integrating the militia proach to pacification. In theory, 1934. In Nicaragua (1926-1933), platoons into the battalion’s rifle the program was simple; a Marine the Marines organized, trained, and squads to form a combined unit. rifle squad would join forces with a commanded the Guardia Nacional Taylor liked Zimmerman’s plan South Vietnamese militia platoon to de Nicaragua. These organizations and forwarded it to Colonel Ed- provide security for local villages. were nonpartisan, native constabu- win B. Wheeler, the regimental CAP’s modus operandi made it laries the Marines commanded until commander. Wheeler also liked unique. While assigned to com- host-nation forces could competent- the plan and pushed it all the bined units, Marines would actually ly assume command.3 way up the chain of command to live in a militia unit’s village. Senior USMC generals in Viet- Walt and Krulak. Both generals CAP was a response to the con- nam had studied as lieutenants liked the idea, and Walt sold the ditions in Vietnam. As the senior such interventions—called “small idea to South Vietnamese General command in the I Corps Tactical wars.” But more than that, As Nguyen Van Chuan. Chuan, who Zone, the Marines were responsi- Commanding General (CG), Fleet was responsible for the Vietnamese ble for securing more than 10,000 Marine Forces Pacific, LTG Victor military forces in Phu Bai, agreed square miles of land that included H. Krulak was responsible for train- to give Walt operational control the five northernmost provinces of ing and readiness of all the Marines over the militia platoons operating South Vietnam. More than 2-1/2 in Vietnam. As CG, III Marine in Taylor’s sector. million people lived in the I Corps Amphibious Force, Walt directed Taylor integrated four rifle area. Using the militia for local se- the operations of all the Marines squads from his battalion with curity made sense; there were not in I Corps. the six local militia platoons in enough Marines to go around. Krulak and Walt began their ca- early August 1965. First Lieuten- The Marines and the U.S. Mil- reers during the 1930s and 1940s ant Paul R. Ek commanded the itary Assistance Command, Viet- under the tutelage of such Carib- combined unit, known as a Joint nam, disagreed on war strategies. bean Campaign veterans as LTG Action Company. Ek, who had U.S. Army leaders wanted to search Lewis B. “Chesty” Puller, Sr., and already served as an adviser to a and destroy the communists in the Major General (MG) Merritt “Red U.S. Army Special Forces unit in rural and less-populated areas of Mike” Edson. In Vietnam, Krulak Vietnam and spoke the language, South Vietnam; the Marines wanted and Walt applied the lessons they was well versed in coun-terguer- to clear and hold the populated ar- had learned about guerrilla fight- rilla warfare. The Marines in Ek’s eas. CAP was a manifestation of the ing.4 combined company were volunteers strategy the Marines felt best suited When the Marines arrived in from the 3d Battalion, 4th Ma- the conditions in Vietnam. rines, and each had been carefully South Vietnam in 1965, they oc- 6 With U.S. Marines living and cupied and defended three enclaves screened by Zimmerman. fighting side-by-side with the Viet- in the I Corps area: Phu Bai, Da The Phu Bai experiment yielded namese people, CAP seemed to Nang, and Chu Lai. CAP grew out promising results. The Marines in- rep-resent an effective, long-term, of an experiment that Lieutenant stilled an aggressive, offensive spir- around-the-clock commitment to Colonel (LTC) William W. Taylor’s it in their counterparts and gave the combating the Vietnamese com- 3d Battalion, 4th Marine Regiment, militia something it had never had munists at the grassroots level. conducted near Phu Bai.5 before—leadership. The Marines CAP worked well in some loca- Taylor’s infantry battalion de- also learned from the Vietnamese, tions; elsewhere, its results were fended 10 square miles and a crit- gaining knowledge of local terrain transitory at best—with villagers ical airfield at Phu Bai. He knew and learning Vietnamese customs becoming overreliant on the Ma- his three rifle companies were not and courtesies. Winning fights 78 July-August 2002 l MILITARY REVIEW against local enemy guerrillas, Ek’s needed to be volunteers, have al- Fort,’” he wrote.15 The platoon must combined unit upset the status quo ready served 2 months in country “conduct an active, aggressive de- by driving the communists out of yet still have at least 6 months fense [of its assigned village] to the villages. left on their tours, have a recom- prevent [communist] incursions Walt seized on the success of mendation from their commanding and attacks directed at the hamlet Ek’s unique company in Phu Bai officers, and once selected, had residents and officials.”16 and approached Vietnamese Gen- to attend a 2-week school, which In July 1967, Corson drafted a eral Nguyen Chanh Thi, his coun- offered instruction in Vietnamese set of standing operating proce- terpart, with a proposal to expand language and culture and small- dures charging each of his platoons the program to include Da Nang unit tactics.10 with six different missions: and Chu Lai. Walt did not need Marine infantry commanders 1. Destroy the communist infra- to put the hard sell on Thi; he was were hesitant to release their best structure within the platoon’s area already impressed by the Phu Bai noncommissioned officers for duty of responsibility. experiment. with combined units; they knew 2. Protect public security; help they would not receive replace- maintain law and order. CAP Expansion ments. And because infantry com- Because of Walt and Thi’s en- 3. Organize local intelligence manders did not always give up nets. thusiasm, CAP stopped being an their best men for CAP, the quality experiment and started becoming 4. Participate in civic action and of combined platoons ranged from conduct propaganda against the an integral part of the Marine outstanding to abysmal, based on Corps’ war in the I Corps area. The communists. the amount of the Marines’ experi- 5. Motivate and instill pride, platoon became the program’s basic ence, proficiency, and maturity.11 tactical unit. A 35-man Vietnamese patriotism, and aggressiveness in Walt acted on these problems. In the militia. militia platoon, and a 13-Marine February 1967, he appointed LTC rifle squad, with one attached U.S. 6. Conduct training for all mem- William R. Corson as his Director bers of the combined-action platoon Navy hospital corpsman, formed 12 for Combined Action. Corson was in general military subjects, leader- the combined-action platoon. This the right man for the job. He had unit lived in and operated out of ship, and language, and increase the fought with the Marines in the Pa- proficiency of the militia platoon so the local village of the militia cific and Korea and had completed platoon.7 it could function effectively without a tour in Vietnam as a tank battal- the Marines.17 U.S. and Vietnamese chains of ion commander. Corson spoke four command remained separate. The Chinese dialects, held a doctor’s de- CAP Problems Marines were only supposed to gree in economics, and had expe- The relationship between the serve as advisers to their counter- rience in unconventional warfare in Marines and the Vietnamese militia parts, and they did—in garrison. Vietnam. He had also served with was the key to CAP’s success. The- In the bush, on patrol, the senior the Central Intelligence Agency in oretically, each combined platoon Marine present became the de facto Southeast Asia from 1958 to 1959, derived its strength from fusing the commander of the combined unit. organizing guerrilla operations two primary elements — the militia From the original 6 platoons against the Viet Minh.13 soldier and the U.S. Marine —into at the end of 1965, the number Corson believed CAP required a single operational entity. Because of combined units grew to 38 its own chain of command and the political climate did not allow platoons by July 1966. By Janu- objected to the existing command Americans to command Vietnamese ary 1967, 57 combined platoons forces, the Marines had no formal arrangement that gave local in- 18 operated throughout the I Corps fantry commanders control of the authority over the militia.