Anyone who is serious about using the Marine CAP concept today must read and study The Betrayal (Hardcover) by William R Corson (Author) (used in good from $9.00 + 3.99 shipping).

BLUF (from McBreen, linked below):

Corson's book is especially interesting given its date of publication. Seven years before the fall of Saigon, Corson predicted a US defeat and a GVN collapse. He directly criticized US policies and leaders. His analysis was immediate and credible, without the benefit of post-war hindsight.

Corson believed in 1968 that the US was farther away from victory than ever, and that the US goal of an independent, self-sufficient Vietnam was impossible. He justified his position by describing the debilitating effects of the totalitarian Saigon government, the ineptness of US military and civilian leaders, and the inconsistency of US government policies.
JMM: I agree with McBreen's words here; and agreed often with Corson generally in the Jurassic Age (for what either is worth).

Bill Corson's book was complete by March 1968, except for finishing touches into April 1968 (when the American KIA total was about 20,000). He was assigned CAP in Feb 1967. When he wrote "The Betrayal", he still could present as its last chapter, "To Stay or Not to Stay ?" as a question.

Bill Corson was a conservative populist and free-thinker. He was somewhat given to hyperbole; but also given to internally logical solutions. However, some of them could not be effected given the real constraints imposed by factors outside of his solution's control. He was a denizen of the "Never Again but ..." school (but I, a fellow dinosaur of similar ilk, don't want to argue its merits in this thread).

"The Betrayal" devotes a chapter ("The Marines' Hamlet War, or What Price Pacification"; pp.174-198) to CAP organization and mission. To decide on "transportability" of the CAP concept, one must also read and study the other chapters (devoted to the SVN political and military context in which CAP operated). The problem (to reach firm conclusions as to "transportability") is that Bill Corson's views on the SVN context was very controversial then; and, I expect, remain so today.

As a "teaser" into Corson, here are two articles generated by USMC officers.

Pelli, Insurgency, Counterinsurgency, And The Marines In Vietnam (1990):

His comments on CAP are taken mostly from "The Betrayal" (his ref "3:") (p.16 pdf):

Basically, the CAP consisted of a Marine rifle squad combined with a platoon of Popular Forces (PF), a local self-defense force. The PF came from the village in which the Marine squad operated. This Marine/PF unit, lived, trained, patrolled, and defended the village, together.

The mission of the CAP was:

(1) Destroy the Viet Cong infrastructure within the village or hamlet area of responsibility.

(2) Protect public security and help maintain law and order.

(3) Protect the friendly infrastructure.

(4) Protect bases and communications axes within the villages and hamlets.

(5) Organize people's intelligence nets.

(6) Participate in civic action and conduct propaganda against the Viet Cong.

(3:184) (JMM emphasis added).
In essence (IMO), a Marine CAP squad was part and parcel of the hamlet Puff (PF) unit - the Puff's "spine" - whose primary mission was to kill bad guys.

In general terms, its members had to be combat-savvy, basically educated in the culture and langange of the villagers; and per Corson ("The Betrayal" p.183):

... most importantly, no manifestation of xenophobia. The final factor is very important in the Other War because the actions of a "gook hater" can result in the loss of an entire hamlet to the Vietcong.
The largest problem in SVN (besides the Communists, who were the larger problem) were the GVN and its ARVN. From Pelli (p.14 pdf):

William R. Carson, throughout his book, The Betrayal, reinforces Krulak's perception. Corson holds nothing back in his derision of the Vietnamese government concerning their inability and lack of real desire to effectively conduct pacification. He says,"...the United States has chosen to support the GVN's grotesque pacification efforts through a massive outpouring of material assistance while ignoring the graft and corruption this assistance has produced." (3:155)

He later says that United States programs designed to improve the lot of the people "... were clearly opposed to the interests of the very officials... we asked to conduct and support these programs." (3:159)
And, from today's second article, McBreen, Notes on: The Betrayal (2006) (p.2 pdf):

5. The GVN was corrupt, cowardly, and incompetent. The GVN did not want social reform. Their indifference to the population, their anti-communist reprisals, and their insatiable greed for drove their own people into popular revolt. The key difference between the north and the south was honesty. GVN officials sold American food to refugees. Million of dollars of US aid went into the pockets of GVN officials. US acquiescence helped the GVN exploit their own people.

Corson noted the irony that "helping the people" was equated with acceptance of the GVN, even though it was universally recognized that the GVN cared little for the welfare of its own people.
As to Afghanistan - in 2006 (p.4 pdf):

9. Notes on Afghanistan 2006. Corson's comments on corruption, officer selection, mirror imaging, and combined operations all apply to Afghanistan today. Corrupt leadership infects and destabilizes entire institutions. This is especially relevant to the Afghan National Army (ANA). We cannot condone corruption. We need a controlling interest in officer selection and assignment. The tendency toward mirror-imaging - with US equipment, tactics, training, and procedures - needs to be balanced with local capabilities and requirements, especially for the embryonic ANA. The multiple coalition organizations in Afghanistan may be more in need of a strong combined headquarters than was needed in Vietnam in 1968.

Corson was a critic whose career suffered because he spoke out. His sometimes strident voice reflected his frustration with US self-delusion on the effectiveness of our chosen strategy. On American hubris and refusal to accept unwelcome facts, Corson wrote, "When one assumes infallibility, it is impossible to change a course of action."
COMMAR has asserted a positive idea. To make it very clear, I'm not in love with US force projection (other than direct actions, if essential) in South Asia in particular, nor with nation (state) building in general.

But, if you're going to do this, here's a positive suggestion.

You've got an augmented squad of expert "killers" and (hopefully) basic "politicians" - which will put military spine into the local Puffs - a total force of roughly 55 people.

I'd suggest (perhaps 5-10 people) as further augmentation (that is, in the same unit with Unity of Command, not Unity of Effort), basic "killers" and expert "politicians" (police, local justice, intelligence, public health) - which might put some political spine into the local Puffs - a total force of roughly 65 people.

BTW: in this context (an insurgency), the "political" program must include a selective violence program.

Regards

Mike