AIR ACTIVITY IN SOUTHEAST ASIA

• Document Type: CREST
• Collection: Library of Congress
• Document Number (FOIA) /ESDN (CREST): LOC-HAK-511-5-7-1
• Release Decision: RIFLIM
• Original Classification: T
• Document Page Count: 5
• Document Creation Date: January 11, 2017
• Document Release Date: February 25, 2011
• Sequence Number: 7
• Content Type: MEMO

No Objection to Declassification in Full 2011/02/25: LOC-HAK-511-5-7-1
MEMORANDUM W W h T5_
DIA, USAF
review
completed.
TGP 9;99P P6!9
MEMORANDUM FOR THE PRESIDENT
FROM: Henry A. Kissinger
SUBJECT: Air Activity in Southeast Asia
of oqr interdiction campaign in Laos.
OSD and JCS reviews
completed
Several months ago, you asked for an assessment of the effectiveness
Our Bombing Campaign in South Laos
Y
Since its inception in 1964, the principal focus of our bombing
campaign in South Laos has been on destroying supplies available for
shipment to South Vietnam.
To do this we attack moving trucks, truck parks, and storage sites
with half or more of our average of 7, 500 sorties monthly. The
remainder of our effort is aimed at reducing the capacity of the
Laotian road-net by attacking the roads. themselves and the crews
that attempt to repair them.
The strengths and weaknesses of the U. S. interdiction effort in
Laos, particularly against moving trucks, largely result from the
operational characteristics of our aircraft:
-- Target Acquisition. Our tactical aircraft, except for the
gunships, are unable to locate their own targets. Instead, targets
are located by FACs (aided by the sensor system) which then
illuminate or mark the area with flares and lead the fighter pilot
to the target. The noise, delay, and illumination involved in
locating a target give the enemy warning of attack and time to take
countermeasures.
-- Bombing Accuracy. Our tactical aircraft generally bomb
from at least 2, 000 feet during the night and higher during daytime,
With regular ordnance, the expected error during daytime when
most bombing is done is about 300 feet for a slow-moving plane
.(A-1) and 500 feet for a fast-moving aircraft (F-4). During night-
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time when there is bad weather the expected errors for both air-
craft types are 1000 feet or more. These bombing errors are very
large given the target size presented by a moving truck or the small
storage dumps typical of Laos.
-- Bomb Lethality. Our standard 500-pound bomb has a lethal
area of about 75 square feet against a truck. With this lethal area
and the average nighttime bombing accuracy, it usually takes 10
500-pound bombs -- two full loads of a slow-moving A-1 -- to ensure
the destruction of a single truck. For the fast moving F-4, four
sorties and up to twenty 500-pound bombs are required to accomplish
this same result.
The enemy knows these characteristics of the U. S. aircraft and the
tactics used in our bombing effort. He has put great effort and
ingenuity into countermeasures that reduce the effectiveness of
our bombing:
-- Weather. The enemy operates almost entirely at night or in
bad weather when U. S. aircraft are unable to acquire targets visually
without warning the enemy and when bombing accuracies are greatly
reduced.
-- Dispersal. The enemy has dispersed his truck convoys and
storage areas so as to reduce target size. Convoyed trucks are often
spaced about 200 yards apart so that no more than one can be
destroyed by a single aircraft. Small storage areas containing five
to ten tons of supplies are sprinkled throughout the countryside.
Bomb Countermeasures. The enemy has learned to locate and
,disarm the mines and delayed-fuse bombs we use. While some delay
and inconvenience is caused, the enemy does not suffer substantial
losses.
-- Road Repair. The enemy has scattered road repair crews
and materials along all the principal routes through Laos. While
we forestall some repairs by the use of anti-personnel mines and
delayed-fuse bombs, the enemy has been able to repair any damage
to its roads in less than two days with only a few hours usually required.
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Because of these effective enemy countermeasures and our technical
limitations, the air interdiction effort has always been relatively
inefficient though not without effect.
Truck Destruction
Because of these difficulties, U. S. pilots in Laos report that only
one out of every five enemy trucks sighted in Laos is destroyed
even though they report destroying more than 5, 000 trucks per year
in 1968 and 1969 and more than 5, 000 in the current dry season.
While these pilot reports represent the best information available,
they may seriously overstate our actual destruction of trucks for the
following reasons:
-- Pilot Error. Rewarded on the basis of reported destruction,
U. S. pilots have an obvious incentive to inflate the damage reported.
While the pilots' reports can be checked against the reports of FACs,
there is little doubt that both probably seriously overstate the damage
suffered by the enemy.
?-- Other Evidence. Post-strike photography has never revealed
the large numbers of disabled trucks in Laos expected from pilot
reports. Out best intelligence is that the enemy's total inventory
of trucks in Laos is substantially less than the number reported
destroyed in some periods as short as a month.
For these reasons, I believe it is likely that our estimates of enemy
truck losses are probably substantially overstated.
Secondary Fires and Explosions
Besides attacking' moving trucks, our bombing effort also hits
enemy storage areas and truck parks. During the current dry
season, our pilots have reported about 20, 000 secondary
fires and explosions compared to 13, 000 in the same period
,last year. In general, these secondary fires account for about two-
thirds of the total supplies that the enemy has lost through our air
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campaign.
However, there is no reliable means of checking these reported
results or determining their significance in terms of enemy personnel
and supply losses. We assign an estimate of the supply tonnage lost
in each secondary explosion but these estimates represent little
more than arbitrary assumptions.
Enemy -Supply Flows
Based on the uncertainties of the reported destruction, the intelligence
community has been at odds over the extent to which the enemy has
enough supplies available to meet hi's requirements in South Vietnam
and maintain his stockpiles in Laos.
The two principal views are:
.q? ,
-- The Air Force and DIA officially accept the pilot's reports
of trucks destroyed and secondary explosions at face value. They
conclude, therefore, that the enemy has only maintained the flow
of supplies into South Vietnam by depleting stockpiles previously
built up in Laos.
-- The CIA believes that the actual supplies lost to the enemy
are substantially less than reported by our pilots. They believe that
the enemy loses about 25% of his supply flow in Laos and has more
supplies available in Laos than he needs to both supply South Vietnam
and build substantial stockpiles in Laos.
Thus, there is a basic disagreement about the enemy's supply
situation in Laos. Our information on actual enemy supply flows
from Laos shows that the enemy is able to vary his supply flows
greatly, increasing them.to levels far beyond his current require-
ments even during periods of intense bombing.
Despite this disagreement about the real results of interdiction, .
there are, however, numerous improvements in our present
campaign that would achieve the same results at a decreased cost
or increase our effectiveness at current expenditure levels. With
DOD plans to reduce our overall air effort in Southeast Asia, it
is critical that we develop as efficient an air effort in Laos as
possible. c
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In this regard, it is also very important to insure that our overall
air effort in all operational areas - Laos, Cambodia, and South
Vietnam - is strong enough to support our military and diplomatic
strategy.
I have prepared a directive to the Vietnam Special Studies Group
telling them to take a hard look at their problems over the next
month. I have discussed this problem with Secretary Laird and
he agrees with this approach.
RECOMMENDATION
That you approve a VSSG study of our FY 71 air effort in Southeast
Asia.
Approve Disapprove
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No Objection to Declassification in Full 2011/02/25: LOC-HAK-511-5-7-1