Foreign Relations of the United States, 1964–1968, Volume XXVIII, Laos

399. Memorandum From the Secretary of the Air Force (Brown) to the Deputy Secretary of Defense (Nitze)¹

Washington, December 11, 1968.

SUBJECT

• Effectiveness of Air Operations in Laos

In my note on the above subject last Friday I promised you my thoughts on the effectiveness of our air operations in Laos during November.

Our tabulation of the effectiveness, as compared with that of Systems Analysis, is as follows. (SA figures are in parenthesis; where there is no number, their paper had none.)

Truck Sightings and Destruction in Laos
	Nov 67		Nov 68
Trucks sighted	4267	(4249)	4562	(3219)3
Trucks destroyed	737	(680)2	322	(199)
Trucks damaged	97	—	105	—
Attack sorties	4399	(4399)	134644	(12500)
Trucks destroyed/sighted (%)	17.3	(16.0)	7.1	(6.2)
Trucks destroyed/damaged/sighted (%)	19.5	—	9.4	—
Trucks destroyed/100 sorties	16.8	(15.5)	2.4	(1.6)
Trucks destroyed/damaged/100 sorties	19.0	—	3.2	—

Several points need to be made relative to the above statistics:

1. Using destroyed/damaged estimates rather than just destroyed doubles the effectiveness against trucks; but the figure is still roughly only one-sixth that of last year.

2. The objective, of interdiction operations—impeding the flow of materiel to SVN—can be accomplished in several ways, e.g., truck kills, creating choke points. A major facet of current operations, Commando Hunt (accounting for over 30% of the above Air Force attack sorties), has as its objective impedance of flow into and through the system, rather than killing trucks. The 7AF preliminary estimate is that November operations impeded up to 75% of the logistics throughput to SVN. A major contributor to this effectiveness was the closure for a large portion of the month of the two major choke points of Ban La Boy (south of Ban Karai Pass) and Ban Pha Nop (south of Mu Gia Pass). Even if 7AF figures are off by 100%, they estimate there would still have been insufficient throughput to enable major stockpiling in SVN.

3. There may be fewer trucks operating in Laos this year than last. Sightings have remained relatively constant, whereas both FAC and reconnaissance sorties each have increased about 50% (from a combined total of 1905 to 2812). Thus, there probably has been more double-counting of trucks this year. 7AF believes, because of their estimate on reduced throughput, that truck sightings this year largely are limited to trucks shuttling within Laos. Any reduction in truck operations could have several possible explanations. It may be, as 7AF believes (and our intelligence tends to confirm) that the choke points have effectively reduced the inflow of trucks. Another possibility is that the NVN by choice are using Laos less. With their newly achieved immunity, it seems logical they would want to reduce their vulnerability by employing NVN routes to just north of the DMZ, then end-running or crossing it. There is at present, however, no road network to support such an endeavor by them of any magnitude; nor does our intelligence indicate any such effort at this time.

4. A very large percent of our recorded truck sightings and kills (almost 90%) in Laos accrue at night. Operations during the day concentrate on lucrative truck parks that Task Force Alpha sensors uncover during the night. The results of this effort are hard to assess in specific truck kills because of limited BDA.

My own conclusions after reviewing the data are twofold. First, it is too early after the bombing halt to make firm judgments about the nature, extent and effectiveness of our interdiction operations in the new environment. Looking solely at truck kills, we did not do so well. On the other hand, if the 7AF estimate on the reduction in throughput is borne out, our air operations should be judged successful. It will take a little longer for us to sort these things out and adjust to the new situation. It may develop that the NVN demeanor and reduced activity will show we have too much air power in Laos to employ it effectively. Alternatively, NVN activity may require all the air power we have, if not in Laos, in SVN along the infiltration routes or, though we hope it proves unnecessary, in renewed operations in the north.

My second point relates to the point in my note of last Friday about prejudging the nature of the war during 1969.⁵ I recognize and fully support the goal of holding the FY 70 budget to the lowest possible figure. Since, however, any planned phasedown of operations in SEA included in the President’s budget almost certainly will become public knowledge once it reaches Congress, I believe we should carefully weigh the impact of such revelations on the negotiations in Paris, on our SEA allies, and on the course of operations in SVN itself.

Finally, I cannot resist pointing out that no more than four months ago, an SA paper in their monthly SEA Analysis Report announced that truck kills were not a good measure of effectiveness, because what counts is whether enough materiel gets through, and besides there is an almost infinite truck reservoir in China and the USSR (as there is). How quickly views change!

We will continue to look into this matter and keep you informed of any significant developments that would provide a more firm basis for making any force structure decisions.

Harold Brown

1. Source: Washington National Records Center, RG 330, OSD/Admin Files: FRC 73 A 1250, Laos 385.1, 1968. Secret. A note on the source text indicates Nitze saw it.
3. SA monthly figures were projected on basis of 1–22 Nov 68 data. Air Force figures are latest available DIA estimates. [Footnote in the source text.]
2. We have been unable to duplicate the Systems Analysis figure of 680. If the intent was to consider as “DIA evaluated” the “destroyed” figure reached by taking 75% of the reported kill and 25% of the reported damaged, the figure would be 577. Our figures eliminate duplication but do not apply the formula. [Footnote in the source text.]
4. 9691 AF tactical aircraft; 661 B–52; 2352 USN; 760 USMC. Total agrees with OSD statistical summary for November, with addition of 661 B–52 sorties. [Footnote in the source text.]
5. Not further identified.