13. Memorandum From the President’s Assistant for National Security Affairs (Kissinger) to President Nixon 1


  • Air Activity in Southeast Asia

On April 17 you directed that air activity levels in Southeast Asia be maintained until July 30. Following that decision, you authorized a [Page 22] Vietnam Special Studies Group evaluation of alternative FY 71 air activity programs for your consideration.2

The Air Effort in Southeast Asia

Since August, 1969 the U.S. has flown an average of about 20,100 tactical air, 1400 B–52, and 640 gunship sorties per month with an annual cost of $3.1 billion. In addition, our allies’ air forces have flown about 4,500 tactical air sorties. The total Allied tactical air effort of 24,600 monthly sorties carried out a wide variety of tasks related to its principal missions of support of ground forces and interdiction:

  • In Southern Laos, about 8,200 tactical air sorties were used in the interdiction campaign, including some 4,400 sorties against trucks or truck parks and 2,100 sorties against enemy roads and bridges. The remainder were used against enemy AAA and other targets.
  • In South Vietnam, roughly 11,400 tactical air sorties (one fourth contributed by VNAF) were used for direct support of ground forces (4,800 sorties) and indirect support (6,600 sorties). Indirect support consisted of strikes against “known” (2,300 sorties) and “suspected” (4,300) enemy locations.
  • In Northern Laos, about 5,000 attack sorties (one third by the RLAF) were employed in support of the RLG forces—some 3,100 in direct support of the Meo guerrillas and another 1,900 sorties in attacks on enemy lines of communication or enemy-controlled areas.

Overall, the U.S. air effort was weighted about equally between interdiction of enemy manpower or supply movements and the support of ground forces in Northern Laos and South Vietnam.

The Alternative Air Programs

In addition to the current sortie levels, (19,000 tactical air sorties) the VSSG study developed two basic alternative U.S. air programs for FY 71:

  • Alternative 1. This includes about 14,000 tactical air, 1,000 B–52, and 1,000 gunship sorties monthly at an annual cost of $2.4 billion. It is similar to the sortie levels planned by DOD for FY 71 within its existing fiscal guidance.
  • Alternative 2. This includes about 10,000 tactical air, 700 B–52, and 1,000 gunship sorties monthly at an annual cost of $1.8 billion.

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While these alternative programs would involve substantial reductions in air activity, there are some key missions that each could carry out:

  • In South Vietnam, maintain direct support of Allied forces at or above recent levels with a substantial increase in air support for RVNAF. In fact, with the accelerated turnover of equipment planned by MACV, the GVN alone should be able by end FY 71 to provide its forces as much direct air support as they have required recently. However, in addition to direct support, the U.S. would be able to provide substantial indirect air support under each of the alternatives.
  • In South Laos, continue an intensive effort to destroy enemy supplies moving to South Vietnam and, depending on the level of enemy effort, maintain the destruction of enemy supplies during this coming year at last year’s level. We could do this by increasing our emphasis on attacking trucks while deploying larger numbers of gunships for this purpose. These converted cargo planes are able to destroy 4.0 trucks per sortie compared to only .3 for the average jet aircraft.
  • In North Laos, continue to provide U.S. support to RLG forces to help them defend against an enemy Dry Season offensive this year as well as providing support if they should themselves undertake a Wet Season offensive.

While each of the alternative Programs would allow us to maintain these capabilities, other areas would receive a lesser emphasis and level of effort than under our current effort. For example,

  • Under Alternative 1 (14,000 sorties per month), the reduction might involve either (a) greatly reducing our attacks on enemy roads and bridges (as opposed to trucks) and storage areas in South Laos or (b) stopping the attacks on “suspected” enemy locations in South Vietnam that now absorb about 40% of our effort.
  • Under Alternative 2 (10,000 sorties per month), the sharper reduction might involve largely ending attacks on enemy roads and bridges and “suspected” enemy locations in South Vietnam.

The assessment of the consequences of reducing overall sortie levels depends on the effectiveness of particular types of strikes in each mission, as well as the overall effectiveness of the entire air effort. To provide this evaluation of effectiveness, the VSSG examined the differences in views on our air activity and the substantive bases for these differences. The main issues to emerge were:

  • In Southern Laos, we have conclusive COMINT evidence that the enemy met his supply objectives during the last Dry Season and maintained enough throughput to South Vietnam to support his forces there. However, we do not know whether the goals the enemy established were lower because of our interdiction, i.e. whether our interdiction [Page 24] merely raises the costs to them of carrying out their plans or whether it scales back their plans.
  • —The JCS believe that our interdiction effort actually limits enemy plans and activity in South Vietnam.
  • OSD and the CIA find that almost no realistic level of interdiction could effectively stop the enemy from moving whatever amount of supplies to South Vietnam he desires; we merely raise the cost to him of carrying out his plan.

The CIA/OSD view is supported by evidence that our interdiction destroys only a small fraction of enemy traffic (13% of his moving trucks). Moreover, we know that the enemy can replace these losses fairly easily (only $200 million in supplies destroyed since 1967) at little cost to North Vietnam itself, since the Soviets foot the bill. Further, in the past, the enemy has proved that he can double his supply flows from year to year and meet his planned throughput goals without operating anywhere near capacity and in spite of our bombing. For these reasons, it seems likely that he can further increase his throughput in the future even at present levels of interdiction or alternatively, that some reduction in effort will not affect the enemy’s plans in the South.

  • In South Vietnam, the direct support of Allied forces absorbs at most only 40% of our air effort in South Vietnam; the major portion of our effort is devoted to strikes against “known” or “suspected” enemy locations with results that are unknowable. OSD finds3 that these strikes are merely “bombing holes in the jungle” with little results. The JCS admit that these strikes are less valuable than direct support but maintain that reducing the pressure on the enemy base areas or LOCs could result in an improved tactical situation for the enemy.

These differences cannot be objectively resolved, though I definitely think that OSD and the CIA have a stronger case than the JCS based on the evidence presented. However, aside from its military effects, any change in overall sortie levels involves a number of broader issues:

  • Resource Implications. The current DOD fiscal guidance includes funds for 14,000 tactical air sorties monthly. If the current program of 18,700 sorties were maintained, other SEA programs would probably have to be reduced by some $600 million. (A U.S. combat division in Vietnam costs about $0.8–$1.2 billion per year.)
  • Enemy Reaction. The study finds that the reductions posed in air activities are “unlikely to bring about any significant shift in North Vietnam’s military behavior.” The JCS believe that any reduction would [Page 25] encourage the North Vietnamese to take a more aggressive posture in both North Laos and South Vietnam.
  • Allied Reaction. Our allies in Southeast Asia, particularly Thailand, will be concerned about significant reductions in U.S. air activity in Southeast Asia. Moreover, the reductions posed would allow the closure of up to two bases in South Vietnam and two bases in Thailand.
  • Military Risks. By “surging” our aircraft and rapidly redeploying one aircraft carrier, we could increase our sortie levels from 14,000 to 22,000 monthly under Alternative 1 and 10,000 to 18,000 monthly under Alternative 2. This should enable us to handle the sortie requirements for a number of major contingencies (enemy offensives in SVN, Laos, or Cambodia, a short intense campaign in North Vietnam, etc.), but we could not handle them all simultaneously or launch an intensive long term campaign against North Vietnam without redeploying forces.

Thus, in choosing a sortie level, the tightness of the present Vietnam budget and the savings that would accrue from a sortie cut need to be balanced against the reactions of our Allies and the North Vietnamese and the effects on our military programs.

The views of your advisors are as follows:

  • —The JCS recommend that the current program of 19,200 tactical air sorties be maintained through FY 71. In the opinion (Tab B)4 of General Abrams and the JCS, any reduction in air activity will “increase the risks to friendly forces and military objectives.” They believe we should seek a supplemental appropriation to pay the extra cost.
  • —Secretary Laird finds (Tab C)5 that no more than 14,000 tactical air sorties monthly are necessary to meet our objectives in SEA and that air activity below this level may well be enough to meet our needs, particularly during periods of low enemy activity or bad weather in South Laos or Vietnam. Therefore, he wants to maintain the forces appropriate to Alternative 1 but, if General Abrams believes it prudent, fly as few as 10,000 sorties (Alternative 2) in the month when enemy activity is low.

Dick Helms believes that the sortie levels proposed by Secretary Laird will prove adequate to meet the needs for support of Meo forces in Northern Laos.

I recommend that you approve Secretary Laird’s recommendation: a maximum FY 71 sortie level of 14,000 tactical air sorties monthly (Alternative 1) with the understanding that actual sortie levels will be less than the funded [Page 26] rate, but higher than 10,000 sorties monthly (Alternative 2). In my opinion, this level of air activity is fully adequate to provide support to the allied ground forces while maintaining some pressure on enemy base areas and supply lines in Laos, South Vietnam, and Cambodia.

Approve Secretary Laird’s Recommendation6

Approve JCS Recommendation

U.S. Bases in Southeast Asia

With a reduction in U.S. air activity, we could make a significant reduction in our personnel and base structure in Southeast Asia. On military grounds, two bases in South Vietnam and two in Thailand could be closed over the coming year. As you know, these closures could lead to concern on the part of our Allies, particularly the Thais:

  • Thailand will be very concerned about the reduction in air activity as it becomes manifest in personnel reductions and base closures. Alex Johnson feels that withdrawal of more than the 10,000 men already planned for FY 71 or closure of more than one U.S. base (Takhli) could cause “serious complications in U.S./Thai relations.”
  • Laos will accept the reduction in U.S. activity if they are given assurance of adequate U.S. support if the North Vietnamese launch a major offensive this Fall. Since we will be able to provide these assurances, even with reduced force levels, the RLG reaction should not be too adverse.
  • South Vietnam already expects some reductions in U.S. air operations over the coming year in line with improvements in VNAF capabilities and U.S. withdrawals. The closure of one U.S. base (Chu Lai) has been long expected and the second (Tuy Hoa) will be no great surprise.

Thus, while the GVN and RLG reaction is not expected to be too adverse, we face a significant problem with Thailand. Because of these political problems, Dave Packard has deferred any decision on the closure of a second base in Thailand even though the closure of the first base (Takhli) is already planned. In regard to Takhli, there are two principal alternatives:

  • Closure. OSD has suggested that Takhli be closed and all U.S. personnel withdrawn by June 1971.
  • Caretaker Operation. Alex Johnson recommends that after the U.S. forces on the base are redeployed, a small U.S. caretaker force (350 men) [Page 27] be retained at Takhli to keep it open until the Thais are able to operate it and its closure will not have serious political ramifications (perhaps until October 1971). I share his view.

Approve Closure of Takhli by June 1971

Approve Caretaker Operation (My recommendation.)7


That you approve the enclosed NSDM (Tab A)9 accepting Secretary Laird’s recommendations that FY 71 sortie levels be planned between 10,000 and 14,000 sorties monthly and that two bases in South Vietnam be closed with the base in Thailand (Takhli) maintained on a standby basis.

  1. Source: National Archives, Nixon Presidential Materials, NSC Files, Box 559, Country Files, Far East, Air Act in SEA, Vol. I, 1970. Top Secret; Sensitive. Sent for action.
  2. According to minutes of a July 30 VSSG meeting held at the Century Plaza Hotel in Los Angeles, the level of air activity was discussed, and the group agreed to pose the issues for decision in a memorandum to Nixon. (Ibid., NSC Institutional Files (H-Files), Box H–3, Vietnam Special Studies Group, 3)
  3. The President underlined “against ‘known’ or ‘suspected’ enemy locations with results that are unknowable. OSD finds” and wrote in the margin, “I agree.”
  4. Attached but not printed is a July 29 memorandum, CM–94–70, from Moorer to Kissinger.
  5. Attached but not printed is a July 23 memorandum from Laird to Kissinger.
  6. The President initialed his approval and wrote the following: “I believe even this is too high on the strategic side—not enough tactical. This study shows the hopeless inadequacy of Air Force. I want a new study for a new approach. This (Laird’s) is just cutting down everything equally. I want a new policy, not just cuts in old programs.”
  7. The President initialed his approval of both options.
  8. The President initialed his approval and wrote the following: “I approve it only temporarily, but I want a new basic policy recommendation in 30 days.”
  9. Tab A is a draft NSDM, printed as revised as Document 20.