While they were not as highly trained for working with host nation personnel as
United States Army Special Forces, in 1965 the
US Marine Corps Combined Action Program (CAP) took on a role of reinforcing and training local village soldiers, although their basic missions differed substantially. (See Comparison with Non-Marine Programs below for details). This small program had a number of phases. At its inception it was unofficial and did not have a standard organization. Some units were called "Joint Action Companies" (JACs). Since, in US military jargon, the word "joint" refers to something pertaining to a combination of forces from different services, and "combined" references a combination of forces from more than one nation, they were, at first, renamed CACs, for "Combined Action Companies." CAC was changed to CAP, for "Combined Action Platoons". From a purely military standpoint, the units were of
platoon, not company, strength. In addition, "cac" is a Vietnamese word for the male generative organ, and the motto included the phrase "suc manh", which means strength. The implications were naturally humorous to the Vietnamese. In the last phase of development, when Marines were no longer permanently assigned to individual villages, the program was renamed to CUPP, for the "Combined Unit Pacification Program." CAP has remained the most common name.
Initial structure To work with the PFs, III MAF instituted the combined action platoon (CAP), consisting of a 13-man Marine rifle squad (if you were fortunate enough to have 13) augmented by a U.S. Navy Corpsman and paired with a 15- to 30-man PF platoon to defend one particular village (The PF was roughly equivalent to the
US National Guard, but with less training and poorer equipment). Each element of the team strengthened the other. The Marines contributed firepower, training, and access to American medical evacuation, artillery and air support. CAPs were generally commanded by a Marine
sergeant, but were sometimes commanded by
corporals. Patrols were often led by lance-corporals. In some cases such as CAP 1-4-1 in 1969 they were commanded by Lance Corporals. Combined Action Platoons were frequently semi-isolated and usually independent units. Headquarters CAPs were sometimes "double" CAPs – i.e.; two CAP squads, one comprising the HQ personnel, the other the patrol and defense element. They were eventually organized as platoons, which in turn formed companies, which were organized into Combined Action Groups (CAGs). Eventually there were four CAGs in I Corps. Originally, the units lived in or near the villages they were affiliated with, eventually in a fortified area. Individual units were assigned to villages in an ostensibly "pacified" area, usually one to a village, though they might serve several other villages in the area. Initially, they were identified by letters and numbers, like line units. Later, numeric designators were used.
Reorganization, 1966–67 According to the Command Chronology of HQ 3rd Marine Division (Reinforced) dated 10 November 1966 (provided by Larry Larsen, formerly of Sub Unit #5); "Combined Action Company (in northern I Corps) joined our rolls as Sub Unit #4, an administrative division of HQ 3rd Marine Division (Reinforced). Later, they operated under Sub Unit #5, then returned briefly to SU #4." (Per pertinent USMC Command Chronologies and other official records.) The CC's "Narrative Summary" for December 1966 mentions various branches supporting CACs Alpha (Houng Thuy), Hotel (Phu Loc), and a fourth portion of HQ 3rd MarDiv (Rein) deployed to Khe Sanh in support of the Senior Officer Present. In southern I Corps, the CAC units (including CAC "India", out of the 1st Bn., 5th Marine Reg., aka;
Cottage Tiger Company, from Dec. 1966 until late 1967, west of Tam Ky, along the Tam Ky river), became part of Task Force X-ray (CAC "India", was later in 1967, known as Sub Unit # 2 of Task Force X-ray), a brigade command of the 1st Marine Division, were placed under the administrative control of the 7th Communications Battalion when the Chu Lai TAOR was turned over to the U.S. Army in late April/May, 1967. Each CAC was operationally supported by the nearest American battalion, whether Marine Corps or U.S. Army. In October 1967, the Combined Action Program underwent a major reorganization with the creation of the 1st Combined Action Group in Chu Lai under Lt.Col. Day, the 2nd Combined Action Group in DaNang and the 3rd Combined Action Group in Phu Bai. All three CAG headquarters reported directly to III MAF. In February 1967, the Narrative Summary notes the establishment of Sub Unit # 5 at Khe Sanh. (That corresponds roughly to the establishment of Oscar Company, then operating under SU #5.) The report mentions building CAP sites, patrols, and other events, but generally doesn't break them down by company or platoon, with references to Alpha, Hotel, and Papa as separate entities. On 15 July 1967, the CC notes that SU #4 was assigned TAD to III MAF, and on 29 July 1967 that the CAC personnel of SU #5 were reassigned to SU #4. In October 1967, the CC notes that "the 3rd Combined Action Group (CAG) was activated as a separate unit under III MAF (operating out of Phu Bai) effective 1 October 1967. The remaining 1 officer and 16 enlisted in SU #4 continued to function as CAG members until normal attrition reduced them to zero effective 30 November 1967.
Roving CAP of 1968 "Beginning in about 1968, the CAP concept underwent some changes. Due to factors such as a high number of attacks and casualties among the static CAPS, the "roving CAP" was started. Roving CAPs had no fixed village – they rotated among two or more villages, and often spent the night in the field. They were very mobile, as opposed to the original static concept, and thus kept the enemy guessing as to where they would be any given night. "Although CAPs sacrificed a degree of control in the villages, the Marines proceeded with the Mobile CAP concept and by 1970 all CAPs were converted. According to the III MAF staff letter, the justification for this conversion included the facts that; the links with the PFs were still intact; it avoided the "mole" mentality of a static position; it denied the enemy information as to the exact location of the unit, thus, reducing casualties; it allowed the Marines to make better use of supporting arms by being outside the populated areas; and allowed the Marines to concentrate their strength by not requiring the unit to guard a base. CAPs were also redesignated beginning about the same time. They went from alpha-numeric designations, (such as Oscar-2), to numeric designations, such as 2-7-4. The first digit designated the group (1–4), the second designated the unit (replacing the letters), and the third designated the platoon.
1970 reduction At the beginning of 1970, Marine strength in the Combined Action Program had reached its peak. Four CAGs were in operation: :*1 CAG under Lieutenant Colonel David F. Seiler, in Quang Tin and Quang Ngai Provinces :*2 CAG under Lieutenant Colonel Don R. Christensen, in Quang Nam :*3 CAG under Colonel John B. Michaud, in Thua Thien :*4 CAG under Lieutenant Colonel John J. Keenan, in Quang Tri In January 1970, the four CAGs consisted of a total of 42 Marine officers and 2,050 enlisted men, with two naval officers and 126 hospital corpsmen. Organized in 20 CACOs and 114 CAPs, these Americans worked with about 3, 000 RF and PF soldiers. The 2d CAG in Quang Nam, largest of the four, consisted of eight CACOs with 36 CAPs and almost 700 Marine and Navy officers and men, while the smallest, the 4th in Quang Tri, had three CACOs and 18 CAPs. With the US participation in the war drawing down, III MAF reduced the CAP platoons as it redeployed its regular forces. On 21 September 1970, the Marines officially deactivated CAP as a separate command within III MAF. In its 5 years of operation, CAPs operated in more than 800 hamlets, containing approximately 500,000 Vietnamese civilians in I Corps. ==Comparison with non-Marine programs==