...What proved most effective in Vietnam were not large conventional operations but targeted counterinsurgency programs. Four — known as CAP, Cords, Kit Carson Scouts and Phoenix — were particularly effective.

CAP stood for Combined Action Platoon. Under it, a Marine rifle squad would live and fight alongside a South Vietnamese militia platoon to secure a village from the Vietcong. The combination of the Marines' military skills and the militias' local knowledge proved highly effective. No village protected under CAP was ever retaken by the Vietcong.

Cords, or Civil Operations and Rural Development Support, was the civilian side of the counterinsurgency, run by two C.I.A. legends: Robert Komer and William Colby. It oversaw aid programs designed to win hearts and minds of South Vietnamese villagers, and its effectiveness lay in closely coordinating its efforts with the military.

The Kit Carson Scouts were former Communists who were enlisted to help United States forces. They primarily served as scouts and interpreters, but they also fought. Most proved fiercely loyal. They had to be: they knew that capture by their former Vietcong comrades meant death.

Phoenix was a joint C.I.A.-South Vietnam effort to identify and eradicate Vietcong cadres in villages. Critics later charged the program with carrying out assassinations, and even William Colby acknowledged there were "excesses." Nevertheless, far more cadres were captured (33,000) or induced to defect under Phoenix (22,000) than were killed (26,000).

There is little doubt that if the United States had placed more emphasis on such programs, instead of the army's conventional strategy, it would have fared better in Vietnam. This is worth keeping in mind today as Sunni towns like Fallujah and Ramadi increasingly turn into an Arab version of Vietcong "villes." The Army is running some valuable counterinsurgency programs in Iraq, but too often it responds to major setbacks with big-unit sweeps (the ongoing one is called Iron Hammer). In a move reminiscent of some of the excesses of Vietnam, the military has taken to dropping 500-pound bombs and sending out M-1 tanks in a largely futile attempt to wipe out elusive foes...