Combined Action Program

The Combined Action Program was a United States Marine Corps counterinsurgency tool during the Vietnam War. It was widely remembered by the Marine Corps as effective. Operating from 1965 to 1971, it placed a 13-member Marine rifle squad, augmented by a U.S. Navy Corpsman and strengthened by a Vietnamese militia platoon of older youth and elderly men, in or adjacent to a rural Vietnamese hamlet. In most cases, the Popular Forces militia members (Nghia Quan) were residents of the hamlet who were either too young or too old to be drafted into the Army of the Republic of Vietnam (ARVN) or the Regional Forces (Dia Phuong Quan). The entire unit of American Marines and Popular Forces militia members together was designated as a Combined Action Platoon (CAP).

The program was said to have originated as a solution to one Marine infantry battalion's problem of an expanding Tactical Area of Responsibility (TAOR). The concept of combining a squad of Marines with local (PFs) and assigning them a village to protect proved to be a force multiplier.

While the exact implementation varied with the stage of the war and local command variations, the basic model was to combine a Marine squad with local forces to form a village defense platoon. It was effective in denying the enemy a sanctuary at the local village level. The pacification campaign seemed to work under the CAP concept, and the Marines fully embraced it. Objectively, there is no solid proof that the CAP concept was a resounding success; however, subjectively the evidence suggests otherwise.

"Counterinsurgency operations and, in particular, the establishment of a foreign internal defense lends itself for the greatest utility of employing a CAP-style organization. Recent operations in Somalia, Haiti, and Bosnia suggest a CAP-style organization could accomplish the assigned mission." In Iraq and Afghanistan, the Marines reinstituted a variant of the CAP.

The CAP concept seems to have been at least partially based on Marine pacification programs in Haiti, Nicaragua, the Dominican Republic, and elsewhere, during the Banana Wars in the late 19th and early 20th centuries. In these programs, Marine units would pacify and administer regions, while providing training and security for local forces and villages. There are also connections to other pacification programs, such as the Philippine Insurrection.

"CAP came naturally for the Marine Corps because counterguerrilla warfare was already part of the USMC heritage. From 1915 to 1934, the Corps had a wealth of experience in foreign interventions fighting guerrillas in Nicaragua, Haiti, and Santo Domingo. For example, the Marines organized and trained the Gendarmerie d'Haiti and the Nacional Dominicana in Haiti and Santo Domingo from 1915 to 1934. In Nicaragua (1926–1933), the Marines organized, trained, and commanded the Guardia Nacional de Nicaragua. These organizations were nonpartisan, native constabularies the Marines commanded until host-nation forces could competently assume command."

"The historical background of Army and Marine counter-insurgency operations, the perceived enemy center of gravity in Vietnam, the strategic aim, and identified critical enemy factors are key to understanding Marine versus Army operational differences on conducting the "Other War." It was these differences and past Marine experience that contributed to the creation of the U.S. Marines' Combined Action Platoon (CAP).

Opinions differ about exactly how and where Combined Action originated, but it seems to have started in August 1965 as a unit drawn from 3rd Battalion, 4th Marines, under William W. Taylor in the Phu Bai(3/4) area. 3/4's TAOR included six villages and an airfield in a ten square mile area. The unit was overextended, and Taylor's executive officer, suggested that they incorporate local militia units into 3/4's operations. Taylor sent the plan to COL E. B. Wheeler, Commanding Officer (CO) of the 4th Marine Regiment, who forwarded it to the III Marine Amphibious Force (IIIMAF) and Fleet Marine Forces Pacific (FMFPAC). Major General Lew Walt and Lieutenant General Victor Krulak, both of whom had fought in the Banana War, saw the potential value and agreed to the proposal. GEN Nguyễn Văn Chuân, the local Army of the Republic of Vietnam (ARVN) CO, gave Walt control of the Vietnamese platoons near Phu Bai.