3. Memorandum From Philip A. Odeen and John D. Negroponte of the National Security Council Staff to the President’s Assistant for National Security Affairs (Kissinger)1
- Abrams’ Vietnam Assessment
This memo reviews critically General Abrams’ recent message assessing the North Vietnamese threat and requesting a series of air operating authorities against targets in North Vietnam. (Abrams’ message is at Tab A.2 Our analytical summary of his threat assessment is at Tab B.3) Specifically we:
- —Assess the intelligence and air material operations cited by Abrams;
- —Review the air operating authorities he requested, pointing to problems and raising questions as well as suggesting optional authorities you might wish to consider;
- —Suggest a series of possible military actions the U.S. might take to deter or cope with a major North Vietnam offensive.
To support his request for additional authorities, General Abrams has provided an intelligence assessment which concludes that a truly major enemy offensive is imminent. He believes that the main enemy efforts will occur in the central highlands of MR II and in northern MR I. A detailed report on General Abrams’ assessment along with our comments is at Tab B.
We do not share General Abrams’judgment that such an offensive is probable; in particular, we question the likelihood of a major enemy push in northern MR I. In any event, General Abrams’ requests can be considered apart from his assessment. Two of his requests relate specifically to a northern MR I offensive, three of the requests relate to the enemy’s increased SAM–AAA–MIG capabilities, and the final request relates to U.S. support for pre-emptive ARVN incursions in Laos and Cambodia.
The specific requests and our comments and suggestions follow.
Air Sortie Levels—1970 and 1971
Abrams points out that enemy initiatives in North Laos and increased hostile air activity this year have forced him to divert air from the Panhandle area where the supply and manpower infiltration is occurring.
There is no question of the accuracy of this statement, but it is mitigated by several considerations:
- —The logistic flow through Laos started later this year, thus there was less need for strikes in South Laos.
- —Most of the aircraft diverted from South Laos missions have been F–4s. These aircraft are relatively ineffective in the interdiction role—the AC–130s do the bulk of the truck killing.
Air Operating Authorities
After assessing the NVN build-up and the serious threat to our aircraft posed by MIGs and SAMs, Abrams requests a series of new air authorities. These authorities would be used “as appropriate” when the “battle for Northern RVN begins.” The requested authorities are:
- —(1) To strike aircraft on three fields in North Vietnam situated at 19° and southwards.
- —(2) To strike active ground control intercept (GCI) radars below 20° used to direct enemy MIGs.
- —(3) To strike any occupied SAM sites within 19 miles of the DMZ and the NVN/Laos border as far north as 19 miles above Mu Gia pass (about 18°).
- —(4) To strike any enemy logistics facilities below 18° (i.e., the southern-most 60 miles of NVN where the major passes are located).
- —(5) To plant sensors in the northern half of the DMZ.
- —(6) To use our aircraft and helicopters to support RVNAF cross border operations into Laos or Cambodia.
Abrams wants these authorities now, stating the situation is developing rapidly and time does not permit him to delay his request until the threat is fully developed.
Each authority is discussed in more detail below.
Attacks on NVN Aircraft on Southern Bases. Abrams states that MIGs based at the three southern-most airbases pose an unacceptable risk to our aircraft operating in the DMZ area. As you will note, he is concerned about MIG operations against SVN and the DMZ areas, not Laos. Yet, to date the MIGs have not attacked or harassed our air operation in the DMZ/Northern SVN areas, only Laos.
This authority would let MACV strike any of the three airfields any time MIGs are based on them. This would essentially permit MACV to strike the airbases constantly, until NVN withdrew the aircraft farther north. Once the MIGs are pulled back (probably to bases above the 19th parallel), the immediate threat to the DMZ would be eased. Since the distances are so small, aircraft from fields north of Vinh could still go after our aircraft over the DMZ. However, our likelihood of detecting them would increase.
This authority would reduce significantly the threat to our aircraft operating over Laos. Most of the attacks on our aircraft over the Trail area as well as the simple incursions into Laotian airspace have been by MIGs based at Bai Thuong or the bases near Hanoi.
If the requested authority seems inappropriate given development thus far, there are a number of lesser options.
- —Authorize a single strike, against all of the occupied bases or any one of the three bases.
- —Authorize a retaliatory strike each time a MIG attacks one of our aircraft or intrudes on SVN or Laotian airspace.
- —Give Abrams standby authority to hit the three bases once we have firm evidence an aircraft from one of them has intruded over SVN/DMZ airspace or attacked or harassed a friendly aircraft operating over the DMZ or SVN.
Authority to Strike GCI Radars South of 20°. Abrams points to the key role played by ground control intercept (GCI) radars and requests authority to strike any active GCI radars below 20°.
The GCI radars are key to the effectiveness of the MIGs operating over NVN/Laos and also play an important role in SAM operations. The GCI radars detect and track our aircraft and this information is passed on to the SAM units as well as to MIG bases. MIGs normally operate under control of the GCI radars which direct them to our aircraft. Since the MIGs have poor radar, without the GCI they are blind except during optimum weather. Thus, knocking out the GCI radars would almost eliminate the MIG threat and reduce the effectiveness of the SAMs.[Page 15]
There are, however, problems associated with striking the GCI radars:
- —Our anti-radar missiles (e.g., Shrike) are not effective since the enemy knows when we launch them and, by shutting off his radars, can avoid being hit.
- —The radars are a small target. We have not been effective in hitting them in the past using conventional bombs except by using a number of aircraft.
- —Radars are easy to repair and in most cases are operational within 48 hours of being hit.
- —Since NVN has overlapping GCI coverage, even if one or two radars are out, the air defense can still operate. Also, since they can be repaired quickly, the Air Force must continue taking precautions (e.g., providing air defense and radar suppression aircraft to protect our B–52s) so hitting the sites does not reduce the diversions of fighter aircraft to the air defense mission.
Despite these problems, some added authority might be considered:
- —Authority could be granted to strike GCI radars controlling MIG aircraft attacking or harassing our aircraft.
- —Authority could be granted for retaliatory strikes against GCI radars that control MIGs against our aircraft.
Attacks on SAMs near the Border. Abrams requests authority to hit any occupied SAM site within 19 miles of the DMZ/Laotian border as far north as 18°. At present, he can only strike these SAM sites if they are preparing to engage our aircraft.
Efforts to strike SAM sites except when they are operating have not been very successful in the past. The SAMs are quite mobile and move frequently. Thus, finding the sites before they turn on their radars is tough. Once they turn on the radar, normally we can hit them if an aircraft is in the area. The authority Abrams requests would, in essence, be to fly armed recce along the border area, searching for SAM sites. Or possibly, it would entail more photo recce, with aircraft dispatched to strike sites that are found in the photos.
Since MACV already has authority to strike SAMs that track aircraft with their radars, there is no clear alternative authority to the new one requested.
Strike Against Logistics Targets Below 18°. Abrams states these facilities would provide direct support for operations in the DMZ, northern SVN area.
Essentially, Abrams wants authority to renew bombing in the area about 60 miles north of the DMZ. This is the broadest of the six authorities requested and the domestic political implications are obvious.
This area also includes the three major passes into Laos, thus it would also be useful in slowing the flow of supplies into the Laotian trail. To be effective, such a campaign would have to be extended for [Page 16] weeks or months. Short raids hurt NVN, but can be offset in a matter of days. Over the next two months, the effectiveness of such an air effort would be limited by weather. The monsoon begins to lift in March, but until then rain and clouds will be the rule.
Some alternative authorities that might be considered include:
- —Providing the requested authority only after NVN intentions to mount major offensive operations in the DMZ northern MR I area are clear.
- —Approving a short, one to three-day raid along the line of the December bombing (it might be wise to wait until the weather improves).
- —Approving a raid against a particular target, if an especially lucrative target south of 18° can be found.
Plant Sensors in the DMZ. Abrams wants authority to place sensors in the northern half of the DMZ. At present, he is limited to the southern half.
This seems like a small but logical action. It should provide better intelligence on enemy activities. We foresee no problems with granting it.
Support RVNAF Operations in Laos and Cambodia. To encourage and make more effective RVNAF cross-border operations, Abrams wants authority to provide fixed wing and helicopter support. This would include troop lift, medical evacuation and resupply.
This appears to be a useful step. There are no legal problems as long as the President is willing to determine these measures necessary to our withdrawing forces from SVN.
Recommendations on Six Additional Operating Authorities Requested by General Abrams on Standby Basis.
- —(1) Air strikes against the MIG bases at Vinh, Dong Hoi, and Quang Lang, all south of the 20th parallel: Selective strikes should be considered.
- —(2) Air strikes against North Vietnamese GCI radar sites south of the 20th parallel: Selective strikes should be considered.
- —(3) Air strikes against SAM sites in the DRV within 19 miles of the DMZ and the DRV–Laotian border to a point 19 miles north of the Mu Gia Pass: Defer until threat further materializes but consider for approval at such time.
- —(4) Air strikes against logistics targets in the DRV south of the 18th parallel: Most controversial authority requested. Defer.
- —(5) Employment of sensors in the northern half of the DMZ: Should approve immediately.
- —(6) U.S. Tactical air and helilift support as necessary for limited ARVN operations across the Lao and Cambodian borders. Should approve.
Other Military Actions. While the threat Abrams is concerned over has not yet developed, especially the threat to MR I, it could develop [Page 17] over the next two to three months. Attention should be given now to military actions we might take at this time or later to cope with the threat, if it materializes.
Some possible actions are discussed below.
B–52s. The 1,000 sorties per month are currently all flown out of U Tapao in Thailand. During Lam Son 719, the sortie rate was increased to 1,200. This could be done again this year.
Higher sortie levels might be possible if two actions were taken, adding more B–52s to the Thai base or flying sorties out of Guam.
- —There are serious limits on space as U Tapao is also the KC–135 tanker base, but a few more aircraft could be based there. It might be possible to increase the sortie rate by another 100 per month (3 to 4 per day) from Thailand.
- —B–52 sorties were flown from Guam from 1965 to 1969. The distances are long and the costs high but by basing two B–52 squadrons there, another 300 sorties per month should be feasible.
Tac Air. Our tactical air could be augmented in two ways, deploying more aircraft to Thailand or increasing our carrier force in the Tonkin Gulf.
It should be possible to add up to three squadrons at our bases in Thailand. These aircraft could fly about 1,500 sorties a month. The manpower problem and costs that this would entail are unclear, but DOD could provide an assessment fairly quickly.
We presently have three carriers in the Western Pacific, two of them normally operate in the Tonkin Gulf. All three could be sent to the Gulf and one more carrier could probably deploy from the West Coast to SEA. Also, the carriers can surge their operating levels for limited periods (e.g., up to 30 days) so the amount of carrier based air support could be increased sharply. The greater carrier presence might also exert some political pressure on NVN. Using the carrier would also be easier than to deploy more aircraft into Thailand, as country clearance will be unnecessary.
Other Actions. Other military actions could be taken to increase pressure on NVN and possibly provide a standby capability should a major offensive take place.
- —A Marine amphibious force could deploy to the area off the coast of SVN. We normally have two battalions afloat in the Western Pacific—both could be sent to Vietnam, and a third battalion could be deployed from Okinawa in a matter of a few weeks.
- —The Naval forces in the area could be strengthened and operate closer to the NVN coast.
- —One to three day strikes against truck parks situated north of Hanoi might be considered. (Two are just north, one is very close to the PRC border.)
- Source: National Archives, Nixon Presidential Materials, NSC Files, NSC Institutional Files (H-Files), Box H–062, Senior Review Group Meetings, SRG Meeting Vietnam Assessment 1/24/72. Top Secret; Sensitive. Sent for action.↩
- Printed as Document 1.↩
- Tab B, an analysis of Abrams’s assessment by Odeen and Negroponte, undated, is attached. The NSC staffers concluded: “In our view, an all-out effort envisioned by Abrams is no more than a possibility; on balance, it is probable that enemy efforts will fall short of the maximum efforts.”↩