Beginning in the summer of 1965, 3/4 (Third Bn, 4th Marines) were faced with an expanding tactical area of operational responsibility (TAOR) and shrinking numbers due to insufficient replacements coming in to fill combat losses. As a result, the Marines began working directly with the Popular Forces, local militias made up of old men and boys too young to be drafted into the Army of the Republic of Vietnam. The plan was approved by General Lewis Walt, the commander of III Marine Amphibious Force and overall Marine Commander in Vietnam at the time, as well as General Nguyen Van Chuan, the local ARVN commander. The Marines were given operational control of the PF platoons near Phu Bai.

Working directly with the PF were General Walt and Lt. General Victor Krulak, both veterans of the Banana Wars in Central America in the ’30s. The Banana Wars were instrumental in the formation of Marine “Small Wars” doctrine, codified in the “Small Wars Manual,” which remained the Marine counter-insurgency manual until it was replaced by FM 8-2, “Counter-Guerrilla Operations.”

From its beginning, the combination of Marines and local Popular Forces were referred to as the Combined Action Program (CAP).  Under the CAP-Platoon concept, a squad-sized element of Marines was combined with a platoon of PF in a local Vietnamese village. These Marines would stay in place for a long time; an entire year or more was not unheard of. They lived with the people of the village and worked with the Popular Forces to secure the village and the surrounding area.

The initial experiment was limited to picked volunteers from 3/4, and began in August, 1965.  There were seven CAP Platoons across I Corps by January, 1966. While it may have begun as a stopgap measure to adjust for the difficulties that 3/4 was facing with its expanding TAOR, it also reflected General Walt’s closeness to the Marine Corps’ Small-Wars Doctrine. From the Small Wars Manual:

“Native troops supported by Marines are increasingly employed as early as practicable in order that these native agencies assume their proper responsibility for restoring law and order in their own country as an agency of their government.” 

With Walt’s sponsorship, the stopgap measure to ensure 3/4 had the strength to secure their own TAOR became a tool of Lt. General Krulak’s “Clear-and-Hold” strategy.

There was a fundamental difference between Westmoreland’s Army’s “Search-and-Destroy” strategy and the Marine-preferred “Clear-and-Hold.” Westmoreland’s technique deliberately separated the Americans from the Vietnamese, ostensibly to avoid “incidents,” but had the effect of alienating the local populace, especially as the area-denial part of the strategy included forcing Vietnamese civilians out of certain villages and then razing the villages to the ground to deny their use to the VC. A Vietnamese peasant, when asked what he thought of the Americans after the completion of a civic-works program conducted in the wake of search-and-destroy operations, was quoted as saying, “How can I remember anything good about the Americans when they did so much bad?”

The “Clear-and-Hold” strategy focused on denying the enemy access to the populace, while the “Search-and-Destroy” strategy was focused on militarily destroying the Vietcong. The difference is perhaps most strongly illustrated by a quote from Mao Zedong:

“There are some militarists who say, ‘We are not interested in politics, but only in the profession of arms.’  It is vital that these simple-minded militarists be made to realize the relationship between politics and military affairs. Military action is a method used to achieve a political goal. While military affairs and political affairs are not identical, it is impossible to isolate one from the other.”

The Marines assigned to the CAP platoons were regular infantrymen. They weren’t given special training, but they worked closely with the locals, established rapport through sharing every facet of life in the war zone with their Vietnamese counterparts. They lived in the villages, defended them each night, and became as close to the villagers as their Special Forces counterparts became with the Montagnards. Some of the depth of this rapport can be found in “I Keep It In My Heart And Wait For You,” a Marine’s recollection of his time with a CAP platoon in 1966-67.

The Combined Action Program did not meet with General Westmoreland’s expectations of how to conduct the war. He considered the Marines less than professional, and argued that the “Clear-and-Hold” strategy wouldn’t work, since he “didn’t have enough men to put a squad in every village in Vietnam.” This dismissal was disingenuous; the idea of “Clear and Hold” was never to put a squad in every village, but to keep the squads out on the edges of what was described as a “spreading ink blot.”  Regardless, Westmoreland was the overall commander, and so “Search and Destroy” was the operating strategy of the war on the ground, and the majority of the villagers had to walk a tightrope between fear of the Americans and fear of the VC.

Eventually, there were 209 villages protected by CAP units. Not one of them, once secured, reverted to VC control.

The CAP concept still stands as one of the more successful COIN strategies the U.S. has yet tried, even if it has never been tested to its full potential. To some extent it was resurrected in Iraq, especially in the neighborhoods of Baghdad. It was met with some success there, as well.

(Featured image courtesy