175. National Intelligence Estimate1

NIE 14.3–66


The Problem

To estimate: (a) the present strength of the North Vietnamese military establishment; (b) its capability to expand; (c) its capability through 1967 to send troops to the South and support them there; and (d) the probable buildup of forces in the South.

[Page 489]


For the purposes of this estimate,2 we assume that North Vietnam will generally continue to pursue its current strategy in the war over the next 18 months.


We estimate the present strength of the North Vietnamese Armed Forces to be slightly over 400,000 with about 375,000 of these in the army. North Vietnam has sufficient manpower to provide a total military force of over 500,000 men without serious strain.
The total Communist force in South Vietnam is estimated at between 260,000 and 280,000. The major combat elements include some 38,000 North Vietnamese troops, approximately 63,000 VC regular main and local forces, and about 100,000 to 120,000 guerrillas.
North Vietnam is estimated to have a current annual capability to train 75,000 to 100,000 individual replacements for infiltration. By making a maximum effort, this total might be doubled. From these, North Vietnam could organize some 24 to 36 infantry regiments per year.
There is considerable margin for error in estimating total Communist losses. Nevertheless, we believe these losses are mounting rapidly. The loss rate has already begun to strain the replacement capability of the VC in South Vietnam, but it appears that current total Communist losses could be replaced, if necessary, from within South Vietnam.
We estimate that the VC could recruit and train 7,000 to 10,000 men per month. The replacement of cadre, however, is probably a problem and is almost certain to become more difficult in the future. By the end of 1967, the loss rate may exceed the estimated capability of the VC to recruit replacements from within South Vietnam, especially if the rate of combat increases. In such case, the Communists might be forced either to scale down their plans for expansion or to step up the rate of infiltration from North Vietnam.
Present evidence suggests that the total infiltration for 1966 will probably be between 55,000 and 75,000 men. These would probably include one or two infantry regiments per month, additional units and combat support battalions, and individual replacements.
We have no reliable evidence of Communist force goals. By the end of 1966, however, the Communist regular force may include 35–40 regiments and other units and number about 125,000 (65,000 VC and 60,000 NVA)—a net gain of about 50,000 for the year. By the end of 1967, this force may grow to over 150,000, provided attrition remains substantially at 1966 proportions.
We believe that current and estimated future capacities of the Laotian road network are sufficient to meet the requirements of the Communist forces in South Vietnam. Even if this capacity could be reduced, say by one-third, and combat activities were to double, we would still estimate that the capacities would be sufficient on an annual basis to support the requirements for the Communist forces at current and future levels. However, at these higher levels of forces and combat, the excess of road capacities over requirements would be reduced during the rainy season.
Maintenance and operation of the North Vietnamese truck fleet in North Vietnam and Laos is a serious problem, and the regime is dependent on the Soviet Union, China, and Eastern Europe for trucks, spare parts, and POL. However, despite truck losses from air attack, breakdown, and retirement, we believe these losses could be offset by imports. The POL requirement for trucks involved in the infiltration movement has not been large enough to present significant supply problems. But local shortages have occurred from time to time and may become significant as a result of attacks on the POL distribution system.
Other channels of supply complement the Laotian corridor, Cambodia has become an increasingly important source of supplies, particularly food. Although sea infiltration has been curtailed, the Communists will probably continue to attempt to resupply their forces by this means, particularly in the delta area.
We believe that morale problems for the Communists will become aggravated in the future. Hanoiʼs problems in implementing its military strategy have increased, and the record of combat must raise questions, at least among some leaders in North Vietnam, as to the wisdom of their long term military strategy.

[Here follows the body of the 18-page estimate.]

  1. Source: Central Intelligence Agency, O/DDI Registry, Job 79–R01012A. Top Secret; Controlled Dissem/Sensitive; No Dissem Abroad. The Central Intelligence Agency and the intelligence organizations of NSA and the Departments of State and Defense participated in the preparation of the estimate. The estimate was submitted by the Director of Central Intelligence and concurred in by all the members of the U.S. Intelligence Board, except for the Assistant General Manager of the Atomic Energy Commission and the Assistant Director of the Federal Bureau of Investigation, who abstained on grounds that the subject was outside their jurisdiction.
  2. The figures in this estimate are current as of June 1966. [Footnote in the source text.]