292. Intelligence Memorandum1
THE EFFECTIVENESS OF THE Rolling Thunder PROGRAM IN NORTH VIETNAM2
1 January-30 September 1966
The Rolling Thunder air offensive against North Vietnam has been accelerated sharply in 1966, compared with operations in 1965. The 59,000 attack sorties flown in the first nine months of 1966 against targets in North Vietnam were about 2.3 times the 1965 effort; the 90,000 tons of [Page 802] ordnance dropped was 2.6 times the ordnance delivered on targets in 1965. The 1966 air operations have also been carried out more efficiently than the 1965 campaign. The average bomb load per attack sortie has increased, and the rate of aircraft losses has been some 58 percent of the 1965 rate.
In spite of these improvements, it is estimated that the cost effectiveness of the air campaign diminished in 1966. The direct operating cost of inflicting a dollarʼs worth of damage in North Vietnam has increased by about 28 percent—from an estimated $6.80 in 1965 to about $8.70 in 1966. The major determinants of this decrease in cost effectiveness have been the far greater proportion of attack sorties accounted for by armed reconnaissance strikes (as opposed to initial strikes on fixed targets) and the geographic concentration of the air effort against logistic targets in the southern areas of North Vietnam, principally Military Region IV.
By the end of 1965, a growing scarcity of fruitful fixed targets outside of sanctuary areas, as well as other operational restrictions virtually forced a continually increasing emphasis on armed reconnaissance. This trend was temporarily interrupted by the strikes against major petroleum storage installations, which began late in June 1966. Strike sorties against JCS fixed-target systems dropped from more than 30 percent of the total sorties flown in 1965 to less than 3 percent in 1966. Armed reconnaissance sorties increased by over 230 percent, from about 17,300 sorties in 1965 to 57,300 in 1966. Almost two-thirds of these—37,000 sorties—were directed at the southernmost areas of North Vietnam, the Panhandle section south of Vinh.
The air campaign over Laos shows similar emphasis on the attempted interdiction of the infiltration network into South Vietnam. Attack sorties flown under the Barrel Roll and Steel Tiger programs increased from 11,000 sorties in 1965 to about 38,000 during the first nine months of 1966. Ninety-five percent of the attack sorties flown in Laos in 1966 were on armed reconnaissance missions.
The major measurable effects on North Vietnam of Rolling Thunder attacks are:
- (1)
- About 20 percent, or 70,000, of the total military forces are engaged directly in defensive programs and countermeasures against the Rolling Thunder program. About 220,000 full-time and 100,000 part-time workers have been diverted to repair, reconstruction, and dispersal programs in North Vietnam and Laos. In 1965 and 1966, from 25,000 to 35,000 persons are tentatively estimated to have been casualties of air attacks in the North.
- (2)
- Physical damage to economic and military targets has also increased. This damage amounted to $65 million in 1965 and an additional $95 million in the first nine months of 1966. Of the latter total, over 70 percent represented damage to economic targets.
Despite the increased weight of air attack, North Vietnam continues to increase its support to the insurgency in South Vietnam. The Rolling Thunder program has not been able to prevent about a threefold increase in the level of personnel infiltration in 1966. The external logistic support needed to maintain the expanded VC/NVA force in South Vietnam has been adequate. In particular, despite the neutralization of the major petroleum storage facilities in the North, petroleum supplies have continued to be imported in needed amounts.
Taking a broader view, during the course of the Rolling Thunder program the North Vietnamese capability to support the war effort has improved.
- (1)
- The capacity of the transportation system, at least as it affects the ability to handle the flow of men and military supplies to South Vietnam, has been increased.
- (2)
- The sizable manpower drain has peaked, unless there is a sharp increase in estimated VC/NVA manpower losses in South Vietnam or a radical change in the nature of the air campaign against North Vietnam. In 1965 and 1966, North Vietnam had to mobilize 80 percent of its physically fit males as they reached draft age. Subject to the assumptions just delineated, this levy could be as low as 50 percent of the 1967 class.
- (3)
- Aid from the USSR and Communist China received in 1965 and 1966 has amounted, in estimated value, to about five times the total caused by Rolling Thunder attacks.
The fact that a large share of the imports now flowing into North Vietnam is not military aid but machinery and equipment seems particularly significant. On the one hand, it reflects a willingness of the major Communist powers to provide additional equipment for war-related industrial facilities, probably encouraged by the fact that the modern industrial sector of the North Vietnamese economy has been largely off-limits to air attack. On the other hand, it suggests that adequate reserves of skilled manpower, electric generating capacity, and other essential inputs are available on a significant scale for conversion to a war-supporting role. While this new emphasis accelerates the ability to support military operations in the short run, it does postpone Hanoiʼs long-run plans for the development of heavy industry.
Nor has Rolling Thunder served visibly to reduce the determination of Hanoi to continue the war. We see no signs that the air attack has shaken the confidence of the regime, and with increased Soviet and Chinese aid to bolster its capabilities, North Vietnam in the short term at least, will apparently take no positive step toward a negotiated settlement. In any event, it is estimated that Hanoi will continue to be insistent on a cessation of the bombings as a prerequisite for negotiations. Analysis of popular attitudes in North Vietnam indicates a continued firmness in support of the regimeʼs policies. Although the long-term effects of the war may have some wearying effect on the population, there is no evidence [Page 804] that it has yet reached a point sufficient to deter Hanoiʼs leaders from their present policies.
Finally, the course of the air campaign in 1966 has had no significant effect on the attitudes of third countries. From the resumption of the bombings in January 1966 to the escalation represented by the bombing of the petroleum storage facilities, third-country attitudes have been, predictably, relatively constant. The unyielding attitude of the North Vietnamese, particularly during the January bombing pause, has had a somewhat sobering impact on some third countries. Indeed, the escalation against POL storage facilities produced a reaction more restrained and less critical than had been anticipated. Among Communist third countries, the USSR and the Eastern European countries would prefer a negotiated settlement because they regard a continuation of the war as potentially dangerous to themselves and in any case as posing an awkward dilemma for them within the Communist world. The Chinese Communists, however, remain adamant in their attitudes toward the war and any steps leading toward a negotiated settlement.
Over and above the measurable effects discussed in the foregoing, the Rolling Thunder program has certain intangible aspects such as enemy morale and determination which are much more difficult to assess. The Rolling Thunder program has been the object of much neutralist criticism and the target of a concerted Communist diplomatic and propaganda campaign. In one sense, this must serve to stiffen Hanoiʼs back; at the same time, the program has become one way Hanoi probably measures US determination—though the extent of US commitment on the ground conveys this determination far more persuasively. Moreover, the Rolling Thunder operation carries some threat of further escalation, and in this way may exert a certain worrisome pressure on Hanoi. On the other hand, if Rolling Thunder were to be terminated at this point without concessions, the United States would be deprived of one form of leverage against Hanoi which it now has.
- Source: Johnson Library, National Security File, Country File, Vietnam, 3 H (1), Appraisal of Bombing of NVN. Top Secret; [codeword not declassified]. The CIA forwarded the memorandum to the President on November 5.↩
- This memorandum was produced by CIA. Aside from the normal substantive exchange with other agencies at the working level, this memorandum has not been coordinated outside CIA. It was prepared by the Office of Research and Reports and was coordinated with the Office of National Estimates, the Office of Current Intelligence, and the Special Assistant for Vietnamese Affairs; the estimates and conclusions represent the best judgment of the Directorate of Intelligence as of 3 November 1966. [Footnote in the source text.]↩