393. Memorandum From the Deputy Under Secretary of State for Political Affairs (Johnson) to Secretary of State Rusk0

SUBJECT

  • Laos Contingency Planning

There does not appear to be the same degree of understanding between State and Defense as I thought had been reached at last Saturday’s [Page 833] meeting at the Pentagon.1 Following that meeting, a staff level memorandum (Tab A)2 was prepared jointly by State, Defense and JCS representatives. (Incidentally, the President has read all the papers referred to herein with the possible exception of McNamara’s memorandum.)3 That memorandum set forth the “Phase Line” approach which I had summarized at the meeting:

  • Phase I. Further buildup outside of Laos;
  • Phase II. Occupation of the Mekong Valley;
  • Phase III. Air action within Laos outside of the Mekong Valley;
  • Phase IV. Offensive ground operations within Laos;
  • Phase V. Air action against North Viet-Nam; and
  • Phase VI. Amphibious operations against North Viet-Nam (pages 3 to 7 of Tab A).

Secretary McNamara has commented on the memorandum (Tab B) in a draft of a memorandum to the President (which I understand has not gone forward—at least formally). This draft memorandum, especially paragraphs 2 and 3 (as well as other indications) discloses a clear and important difference of view.

Defense does not accept the concept that Phase II (occupation of the Mekong River Valley, a joint State-Defense-JCS concept for which is attached as Tab C)4 has any political or military justification in itself. This is clear not only from Secretary McNamara’s draft memorandum but also from the tenor of JCS cables to the Field Commanders, which describe planning for this phase only in terms of seizure of river crossing points as a prelude to a larger military operation in the Laos panhandle.

Because the Defense position would confront the President with such a categorical choice between the loss of Laos and the likelihood of all-out war with North Viet-Nam, it seems to me incumbent to make clear what all of your staff is convinced is the fact, that there are intermediary alternatives which are politically justifiable and which appear militarily defensible. Much careful work has gone into this conclusion. The following is a summary of our conclusions.

1.

Can we afford to let Laos go by default? Much of Laos is already in Communist hands and therefore this question addresses itself only to that portion held currently by the RLG. The RLG now holds the Province of Sayabouri, a thin slice along the Province of Luang Prabang down to the Vientiane plain, and then the Mekong River Valley from that plain south to and including the Plateau de Bolovens at the Cambodian border.

[Page 834]

Historically, the Mekong Valley has always been an area of contention between forces confronting each other in this part of the world. Therefore, a control of this valley has major psychological significance to those states neighboring on it. If control of the valley were ceded to the Communists, the political shock effect in Thailand and South Viet-Nam would be severe and would cause internal political repercussions of an adverse nature, the limits of which would be difficult to predict. In Cambodia, Communist control of the valley would mean for the first time a direct land confrontation between Prince Sihanouk and Communist power. From Sihanouk’s past behavior, it is predictable that he would seek an accommodation with the Communists and would align his international policy much more closely with theirs.

From a strategic point of view, loss of the valley to the Communists would put them in a position from which the North Vietnamese could maximize their infiltration of men and equipment down the road and river network and, with increased pressure on Cambodia, might be expected to use the favorable Cambodian terrain to complete the “freeway” for their military effort into South Viet-Nam. Consequently, the problem of the defense of South Viet-Nam would be sharply exacerbated. If the Communists obtained full control over the east bank of the Mekong, with its relatively good north-south road, the defense of Thailand would be much more difficult. (INR and Rand studies—Tabs D and E).5 As General Harkins pointed out in a recent cable to Secretary McNamara,6 “If the Communists gain complete control of Laos, infiltration activity into Thailand and South Viet-Nam, and I add Cambodia, can be expected to increase rapidly. As expressed above, this will make the problem of holding all of Southeast Asia more difficult. I believe in this case U.S. troops will be required in Southeast Asia for a long time (as in Korea) to prevent ultimate loss to the Communists. This would be the price of buying time to develop and stabilize popular support of these governments and provide them adequate self-defense capabilities. As in Korea, Taiwan, and Europe, our military aid troop commitments would depend on international political solutions.”

2.

What is the value of the cordillera? An analysis of all available information on the current infiltration routes into South Viet-Nam through the cordillera (see Hilsman memo to Secretary [Black Covers]7 “Infiltration Routes into South Viet-Nam: A Round-Up of Available Information”)8 reaches the following conclusions: [Page 835]

A.
The trails have been used principally to bring in cadre and probably some organized units.
B.
Over them have also come limited quantities of specialized supplies such as radios and medical supplies. These, though important, are not decisive considering total Viet Cong needs.
C.
Given the nature of the terrain, it would be extremely difficult for the Communists to improve the routes they now hold sufficiently for them to be used as a major source of supplies and equipment. They could probably, however, step up the number of personnel using them.
D.
Since the present routes traverse considerable distances inside South Viet-Nam before reaching the main combat areas, they are vulnerable to counteraction by ranger companies and montagnard guerrillas.
E.
Although present political considerations undoubtedly make the Communists reluctant to make full use of the routes through Cambodia, the more favorable terrain there makes them the more dangerous should the Cambodian resistance to this type of infiltration weaken.

Although the present routes are vulnerable to counteraction inside South Viet-Nam, occupying the panhandle would undoubtedly be even more effective. On the other hand, General Harkins says that it would take “a considerable military effort” to get control of the panhandle and that this would still not completely stop infiltration of individuals in small cadres.9

3.

Is the Mekong River Valley defensible? The Rand Corporation has recently completed a study on the military geography of Laos. INR has analyzed this study (Tab E) and believes that it supports the conclusion that U. S. forces holding those dominant geographical features of the terrain which were in the hands of the RLG at the time of the cease-fire on 3 May 1961 could control the Mekong River Valley in “a feasible defensive operation”.

It is also worth noting that the Rand Study (page 13) points out that the densely forested mountains of the north and east of Laos are “much more favorable for guerrilla and subversive action” than the generally open, level, or gently rolling terrain of the Mekong lowlands. With respect to unconventional operations, in sum, the Rand Study concludes that “the natural advantages are on the side of the defending force” (meaning the force holding the Mekong Valley). Although the Communists would undoubtedly attempt to step up guerrilla activities in either case, the implication is strong that a force occupying the whole of the panhandle would have a much more serious guerrilla war problem than a force occupying only the Mekong Valley.

4.
What are the probable Communist responses to U.S. military action? SNIE 58–5–62 (Tab F10), in which the Defense Department representatives [Page 836] have concurred, estimates that the probable Communist reaction to a U.S./SEATO investment of the Mekong River Valley would be the introduction of additional forces into Laos and certain harassing activity. “We do not believe, however, that the Communist forces would attempt to drive the U.S. troops from the areas they occupy.” On the other hand, the same SNIE estimates that the Communists would “resist strenuously a U.S. effort to clear the area to the South Vietnamese border. They would almost certainly attempt a rapid logistics buildup, further strengthen the North Vietnamese forces, and probably introduce Chinese Communist forces.”
5.
Does occupation of the Mekong River Valley serve U.S. objectives? When the U.S. made the decision to put U.S. ground forces on the continent of Southeast Asia, we knew that we could not withdraw those forces unless there were some political justification for that withdrawal. Defense must therefore be prepared to accept the immobilization of a certain number of U.S. forces in this area commensurate with our political objective, which is to prevent Communist control of Southeast Asia. If we are to retain this objective, but cede the Mekong River Valley to the Communists, the number of troops immobilized and the length of their stay will, as General Harkins has indicated, increase considerably. If, on the other hand, we move forces into Laos to establish control of the Mekong Valley, there would be international pressures to place the Geneva Agreements into effect and to secure the mutual withdrawal of North Vietnamese and U.S. forces. There would be no similarly acceptable pressures for withdrawal of our forces from Thailand.

Occupation of RLG-held territory to ensure or restore the cease-fire and permit progress toward negotiations would be defensible internationally. An offensive sweep across the panhandle, on the other hand, would probably not be defensible internationally even in the face of a general attack on the RLG prior to U.S. occupation, since the Communists would probably be successful in charging Phoumi with provocation. Such a sweep across the panhandle would be defensible only if the general Communist offensive were continued against U.S. forces after they had entered Laos to restore the cease-fire.

The real questions, of course, concern the conditions which could be tolerated by our forces in an occupation of the Mekong River Valley. There is agreement that a general attack on our forces would justify sharp reaction by the U.S. Differences arise in the degree of harassment which these forces might be required to accept and in the amount of Communist consolidation which could be tolerated in the cordillera. Your staff feels that there are definite limitations on the amount of harm which the Communists can do to our position in Southeast Asia by control of the cordillera and that we have means of limiting such harm. In any event, I do not feel we can or should seek from the President any [Page 837] advance determination of exactly the circumstances under which we would move from an occupation of the Mekong Valley to an offensive into the panhandle. Above all, I do not feel that this is a decision that can be left to the military commander on the ground, no matter how able he may be.

  1. Source: Department of State, Central Files, 751J.00/6–962. Top Secret. Drafted by Sullivan, Hilsman, and Johnson.
  2. See Document 384.
  3. See Tab A to Document 387.
  4. Document 386.
  5. Tab C was a slightly revised version of Attachment 1 to Document 383.
  6. Neither Tab D nor E is printed, but see footnote 3, Document 387.
  7. In telegram MAO 21127, DA IN 236047, June 4. (Washington National Records Center, RG 330, OSD Files: FRC 66 A 3542, Laos 381)
  8. Brackets in the source text.
  9. Not attached and not found.
  10. See footnote 7 above.
  11. See Document 375.