Foreign Relations of the United States, 1955–1957, Vietnam, Volume I

254. Memorandum From the Executive Secretary (Lay) to the National Security Council¹

Washington, September 16, 1955.

SUBJECT

• U.S. Policy in the Event of a Renewal of Aggression in Vietnam

REFERENCES

• A. NSC 5429/5, para. 5–d
• B. NSC Action No. 1415
• C. Memo for NSC Planning Board from Executive Secretary, same subject, dated August 16, 1955²

The enclosed study, prepared by the Joint Chiefs of Staff in accordance with the report adopted by the Planning Board on August 15 (Reference C) is transmitted for the information of the National Security Council and the use of the NSC Planning Board in its further consideration of the subject in connection with carrying out NSC Action No. 1415–c.

Also enclosed is a memorandum by the Deputy Secretary of Defense transmitting and commenting on the JCS study.

At the request of the Deputy Secretary of Defense, these papers are being given a special limited distribution. It is requested that special security precautions be observed in their handling and that access to them be strictly limited on a need-to-know basis.

James S. Lay, Jr.

[Here follows a table of contents.]

[Enclosure]³

Memorandum From the Deputy Secretary of Defense (Robertson) to the Executive Secretary of the National Security Council (Lay)⁴

Washington, 15 September 1955.

SUBJECT

• U.S. Policy in the Event of a Renewal of Hostilities in Vietnam

1. I transmit herewith for the information of the National Security Council a memorandum by the Joint Chiefs of Staff on the above subject, which was prepared in response to a request deriving from NSC Action No. 1415–c. I believe the Joint Chiefs of Staff analysis to be generally sound. We may wish to make some further comments on certain of the logistic implications outlined in Appendix “B”, but in order to expedite NSC consideration of the problem, I am transmitting the Joint Chiefs of Staff memorandum at this time, with the understanding that we will be prepared, if necessary, to discuss it in greater detail in the Planning Board. I trust that this material will prove of substantial assistance in the Council’s work on the policy question under consideration.

2. There are attached for information the two earlier memoranda (dated 11 February⁵ and 19 August 1955⁶) to which reference is made in the basic JCS memorandum. There are also furnished copies of the two cables⁷ discussed in the latter of these memoranda.

3. Because of the sensitivity of the documents attached it is requested that they be distributed on a strictly limited, need-to-know basis. Extra copies of the cables are furnished so that they may be appended to the papers you distribute without the need for your office to reproduce them.

Reuben B. Robertson, Jr.

[Subenclosure]

Memorandum From the Joint Chiefs of Staff to the Secretary of Defense (Wilson)⁸

Washington, 9 September 1955.

SUBJECT

• U.S. Policy in the Event of a Renewal of Aggression in Vietnam.

1. This memorandum is in response to a memorandum by the Assistant Secretary of Defense (ISA), dated 19 August 1955, subject as above,⁹ in which he requested the Joint Chiefs of Staff to determine the implications and requirements of U.S. military operations, with and without atomic weapons, (1) to repulse and punish overt Vietminh aggression, or (2) to destroy Vietminh forces and take control of North Vietnam.

2. The Joint Chiefs of Staff consider that for the near future, unassisted South Vietnamese forces will be capable of only limited resistance against determined overt aggression by Vietminh forces. Without a warning period in which U.S. preparatory actions were taken, a portion of South Vietnam would probably be overrun, and the integrity of elements of the defending forces would be impaired or lost.

3. Under the foregoing probable conditions, the first task operations to repulse and punish overt Vietminh aggression would include:

a. Immediate U.S. naval and air attack against Vietminh forces.

b. Initial reliance upon Vietnamese ground forces supported by U.S. naval and air operations to oppose the aggression.

c. Early movement forward of mobile U.S. forces, for the purpose of conducting joint operations for tasks beyond the capabilities of South Vietnamese forces.

d. The provision of direct and increased logistical support to Vietnamese forces.

4. The Joint Chiefs of Staff consider that the second task, to destroy Vietminh forces and take control of North Vietnam would require an extension of the operations listed in paragraph 3 above, with the ultimate objective of creating conditions under which the forces of South Vietnam, the Associated States or SEACDT could assume responsibility for accomplishment of the second task. This would require a major campaign of pacification, accompanied by the development of additional indigenous forces for an enlarged mission. Such a campaign would be initiated by joint and combined operations in the Tonkin Delta area to seize bases and other important objectives and to cut supply lines from Communist China.

5. The success of intervention by U.S. forces in a swift and decisive action is believed dependent on the military energy and solidarity of the Vietnamese, the extent of warning and preparations made before an attack, the restriction imposed on U.S. military operations, and the season of the year. It is estimated that operations to carry out the first task could be terminated in a few months to one year to check aggression, but a longer time might be required to clear out all the Vietminh back to the 17th parallel. The time needed for carrying out the second task cannot be accurately estimated. Should employment of atomic weapons not be authorized a longer time would be required. Additionally, although the concepts would not require change, this restriction on the use of atomic weapons would not permit the most effective employment of U.S. armed forces and consequently might require greater forces than the U.S. would be justified in providing from the over-all point of view.

6. With reference to U.S. force requirements:

a. Naval forces currently assigned to the Pacific Fleet are ready to accomplish initial naval missions. For the first task one carrier task force, a bombardment force, an appropriate amphibious force, Marine detachments, and logistical resupply forces would be required. For the second task some augmentation in U.S. naval forces would be required.

b. Assuming the use of atomic weapons, Air Force requirements for either task would be two to three tactical Air Force wings and SAC forces as necessary. Assuming no use of atomic weapons, there would be an increase of tactical air requirements, particularly for the second task; however, sufficient air bases are not available to position these larger forces. For both tasks, in addition to the forces above, tactical airlift for one airborne RCT and strategic airlift for one division would be required.

c. For the first task, ground forces in the magnitude of two to four U.S. divisions should be available for operations listed in paragraph 3 above. For the second listed task, it is estimated that a total strength of up to eight U.S. divisions would be required. Requirements for U.S. ground forces would be subject to reduction to the extent that effective forces were provided by other Manila Pact countries or by other Allies.

d. Forces available are as shown in Appendix “A”.¹⁰

e. Logistic requirements and implications are summarized in Appendix “B”.¹¹

7. The effects upon other U.S. military commitments as a result of these operations by U.S. armed forces in Southeast Asia would be significant and in proportion to the amount of diversion of forces to this area and the speed with which these diverted forces are returned or replaced. However, the Fleet Marine Forces and certain Army forces in the Pacific could be deployed to the area temporarily without serious effects on other military commitments and without necessitating partial mobilization or substantial increases in force levels and budgetary support.

8. The strongest deterrent to Vietminh aggression, and, at the same time, the most effective preparatory military step would be the stationing of U.S. forces in South Vietnam. However, this course of action is prohibited, prior to an act of aggression, by the terms of the Geneva agreements. The next most effective deterrent would be to add to the deterrent effect of the forces presently deployed in the Far East by deploying mobile ground forces of approximately corps strength together with naval and air forces into the Southeast Asia area prepared for rapid commitment to South Vietnam. Nevertheless, the Joint Chiefs of Staff are of the opinion that at this time the major threat to South Vietnam continues to be that of subversion, and until there are more conclusive indications of overt aggression, it is not considered that additional forces should be deployed to the Southeast Asia area.

9. Preparatory military steps which might be taken are:

a. Continued efforts to increase the effectiveness of the South Vietnamese armed forces for countering external aggression as well as maintaining internal security. In this connection, reference is made to memorandum for the Secretary of Defense, dated 19 August 1955, subject: “Revised Force Bases for Vietnam”.

b. Continued improvement of bases in Thailand and Cambodia for use in support of Vietnamese forces.

c. Special training for selected Vietnamese personnel, outside of Vietnam if necessary, in U.S. methods of exploiting air and naval support in ground operations. Instruction might also be provided in the special tactics and techniques of employing atomic weapons support.

d. Accelerated progress in the military aspects of the Manila Pact including combined training. Exercises could be timed to attain optimum psychological and political impact; for example, joint and combined maneuver type exercises in the Philippines or Thailand could be scheduled immediately prior to the Vietnam elections to indicate progress made by non-Communist nations toward collective security, and readiness on the part of Manila Pact nations to carry out their commitments.

e. Aside from the foregoing, preparations can be made for the rapid movement of tactical air control parties and some ground liaison, logistic and communications personnel to Vietnam, in advance of major U.S. formations, to insure an early capability for U.S. supporting operations. Similarly, preparations can be made for early deployment of special U.S. forces to provide a capability for ground delivery of atomic weapons.

10. In the early stages, Vietminh aggression would probably be characterized by a fluid situation with dispersed clashes between opposing forces. In such operations, the opportunities for employing atomic weapons would not justify significant reductions in early force requirements. During later stages, however, suitable targets could be expected to develop as a result of friendly efforts to force concentrations or particularly if the Chinese Communists should intervene overtly. Use of atomic weapons should result in a considerable reduction in friendly casualties and in more rapid cessation of hostilities. In any event, no prohibitions should be imposed on the use of atomic weapons, or on other military operations, to the extent of precluding effective military reaction as the situation develops. The Joint Chiefs of Staff consider that if atomic weapons were not used, greater forces than the U.S. would be justified in providing would probably be needed.

11. The Joint Chiefs of Staff reiterate the view expressed in their memorandum, dated 11 February 1955, subject: “Concept and Plans for the Implementation, if Necessary, of Article IV, 1, of the Manila Pact,”¹² that the United States cannot guarantee the territorial integrity of any member nation (of the Manila Pact), but at most can help secure the independence of those countries whose peoples desire it and who are willing to undertake the responsibilities of self government. This appears to be particularly applicable to protected, non-member countries.

12. The foregoing is a rough estimate of the requirements. A more definitive answer cannot be made until the Commander in Chief, Pacific, provides a plan which he is presently developing.

13. The Chairman, Joint Chiefs of Staff, did not participate in the action of the Joint Chiefs of Staff outlined in this memorandum.

For the Joint Chiefs of Staff:

N.F. Twining
Chief of Staff
United States Air Force

1. Source: Department of State, S/P–NSC Files: Lot 62 D 1, NSC 5519 Series. Top Secret.
2. Document 244.
3. This enclosure and its subenclosure are also printed in United States–Vietnam Relations, 1945–1967, Book 10, pp. 1001–1006.
4. This memorandum was classified Top Secret.
5. See Document 38.
6. Document 247.
7. See Documents 241 and 242.
8. This memorandum was classified Top Secret.
9. Not printed; filed as enclosure A to a note by the Secretaries to the JCS (J.C.S. 1992/474), August 22. (JCS Records, CCS 092 Asia (6–25–48))
10. Appendix A, “Availability of U.S. Armed Forces,” is not printed. For text, see United States–Vietnam Relations, 1945–1967, Book 10, pp. 1007–1011.
11. Appendix B, “Logistic Requirements and Implications,” is not printed. For text, see ibid., pp. 1012–1015.
12. See Document 38.