Foreign Relations of the United States, 1964–1968, Volume IV, Vietnam, 1966

61. Memorandum From the Joint Chiefs of Staff to Secretary of Defense McNamara¹

JCSM–76–66

Washington, February 3, 1966.

SUBJECT

• Consequences of an Enclave Strategy (U)

1. (U) Reference is made to:

a. Your memorandum for the Chairman, Joint Chiefs of Staff, dated 17 January 1966, on the above subject.²

b. “A Communication on Vietnam from General James M. Gavin,” Harperʼs magazine, February 1966.³

c. JCSM–652–65, dated 27 August 1965, subject: “Concept for Vietnam.”⁴

d. JCSM–811–65, dated 10 November 1965, subject: “Future Operations and Force Deployments with Respect to the War in Vietnam (U).”⁵

e. JCSM–16–66, dated 8 January 1966, subject: “Air Operations Against North Vietnam (U).”⁶

f. JCSM–41–66, dated 18 January 1966, subject: “Air Operations Against North Vietnam (NVN) (U).”⁷

2. (U) In response to your request, reference 1 a, the Joint Chiefs of Staff have studied the proposals outlined in General Gavinʼs letter to Harperʼs magazine, reference 1 b. Their analysis of the military consequences of the adoption of such an “enclave” strategy follows.

3. (S) For this analysis, it has been assumed that the United States would continue to seek a stable, noncommunist government in South Vietnam (SVN) and would assist the Government of Vietnam (GVN) to defeat the Viet Cong (VC) and to extend GVN control throughout SVN.

4. (TS) Coordination of current strategy with the GVN is essential to successful operations. If forced to accede to such an “enclave” strategy, the political/military structure of the GVN is likely to collapse under the resulting stresses. For example:

a. The GVN would probably lose its existing support and measure of control in areas outside enclaves.

b. Experience to date has established the fact that without military presence the communication among and movement of people between enclaves, the maintenance of commercial activities and economic programs, and the day-to-day functions of government would essentially cease.

c. If the RVNAF were to remain In areas beyond the enclaves, they must then combat the increased VC/PAVN forces essentially without the aid of the United States and other Free World ground forces and perhaps also without their direct advice and logistic support. Military coordination between the United States and the RVNAF could collapse.

d. If, on the other hand, the RVNAF were to withdraw to the enclaves, they would abandon the paramilitary forces, as well as all province, town, and hamlet officials, in areas outside the enclaves to the enemy and permit the communists to consolidate their control over the entire countryside beyond the enclaves.

e. The obvious and prolonged concentration of US forces in defensive enclaves could incite anti-US sentiment.

5. (TS) An essential element of the “enclave” strategy advanced by General Gavin is the requirement for fewer US forces, presumably not exceeding current in-country strength of about 200,000. CINCPAC estimated⁸ that this force level could defend essential base areas and key LOCs and secure 10 per cent of the land area (encompassing about 40 per cent of the population) against the enemy threat existing at that time. In view of the increased VC/PAVN threat, commitment at the above level of forces to such an “enclave” strategy would not now insure the military security of essential base areas and population centers nor protect sufficient food-producing land to feed the population. Thus, a determined defense of enclaves of adequate size and number could now require US forces well in excess of 200,000.

6. (TS) Such an “enclave” strategy would not necessarily reduce casualties. Ultimately, a defensive posture in the enclaves might well result in casualties on at least the same scale as a more balanced strategy. In the ʼ“enclave” strategy, loyal Vietnamese, particularly local officials, must either flee to the enclaves or face VC reprisals. Permitted to consolidate their forces, their supply system, and their base areas, the VC and PAVN units would be in a position to launch more carefully-planned and highly-selective attacks—probes or large-scale efforts—against the enclaves. To the degree we surrender control of the countryside to the VC/PAVN, we facilitate their capability to employ longer range weapons. In addition, there probably would be a heavy influx of refugees, thus offering a channel for VC infiltration difficult to close. Such infiltrators could increase casualties.

7. (TS) General Gavinʼs letter implies that the expansion of our present actions would lead to a direct armed confrontation with the Chinese communists (ChiComs). In the judgment of the Joint Chiefs of Staff, such a confrontation is more likely to occur from a gradually increasing ChiCom involvement which leads almost imperceptibly into such a war than through a deliberate and abrupt decision to take on the United States. The defensive nature of the enclaves might further stimulate rather than discourage the ChiComs to exploit what they could regard as a weakening of US resolve in Southeast Asia. The Joint Chiefs of Staff believe that a deliberate ChiCom decision to risk direct armed confrontation, including the magnitude, character, and time-phasing of the introduction of ChiCom forces, will result from their assessment of US resolve and inherent risks to the attainment of Chinese objectives. Such a decision would not be the direct reaction to the deployment of sizable US forces to SVN nor to air operations against North Vietnam (NVN) which the Joint Chiefs of Staff have proposed. Moreover, the ChiComs would be invalidating the basic premise of communist “Wars of National Liberation” by bringing major powers into direct confrontation. However, as US force buildup continues, the likelihood of ChiCom support of the VC/PAVN will increase, especially as the United States approaches attainment of its objectives in SVN.

8. (S) The balanced strategy outlined in references 1 c and 1 d is designed to achieve US national objectives and to assure that, if the United States enters into negotiations to achieve these objectives, it does so from a position of strength.

9. (S) The Gavin “enclave” strategy, on the other hand, appears to depend upon two underlying implications: (a) that the withdrawal of US forces to enclaves would bring the communists to the negotiating table; and (b) that the United States is willing to negotiate itself out of SVN by forfeiting its objectives. These implications are highly questionable. In contrast, the US/GVN would be bargaining from a position of weakness due to the cessation of offensive operations in SVN, with only that leverage afforded by such bombing as might be continued in NVN to persuade the VC/DRV to yield the gains they acquired by default. Additionally, the VC, having undisputed control of the predominant land areas in SVN, could seek world recognition as the de facto government of SVN, or, alternatively, annex their holdings to NVN.

10. (S) General Gavin also proposes that the United States desist from bombing NVN. The serious consequences of halting air operations in NVN, set forth in references 1 e and 1 f, would be in addition to those foreseen for an “enclave” strategy in SVN. If the “enclave” strategy were implemented without air operations in NVN, this remaining major inducement toward negotiations and source of leverage would thereafter be forfeited, and the VC/PAVN would have unimpeded access to support from the north. The Joint Chiefs of Staff consider that the offensive air operations against the DRV are an essential element of a balanced US strategy. They consider it no less so in an “enclave” strategy. These air operations are a principal military means for inhibiting the buildup and support of communist forces in SVN and for persuading the DRV to cease its aggression.

11. (TS) The Joint Chiefs of Staff do not support such an “enclave” strategy since it contains significant deficiencies, and the advantages claimed are more illusory than real. By forfeiting the initiative, abandoning solid negotiating leverage, conceding large land areas to the enemy, and alienating the GVN and other friendly governments, the “enclave” strategy, in effect, abandons national objectives. The military consequences would, in their judgment, lead to US/GVN defeat in SVN or ultimate US abandonment of Southeast Asia.

For the Joint Chiefs of Staff:

Earle G. Wheeler⁹

Chairman
Joint Chiefs of Staff

1. Source: Johnson Library, National Security File, Country File, Vietnam, vol. XLVII. Top Secret.
2. Not found.
3. Published January 16. Gavin proposed that the United States stop the bombing of North Vietnam and the escalation of the ground war, limit U.S. troops to the defense of several enclaves along the South Vietnamese coast, and renew efforts to “find a solution through the United Nations or a conference in Geneva.”
4. For text, see Foreign Relations, 1964–1968, vol. III, pp. 356–363.
5. Not printed. (Johnson Library, National Security File, Country File, Vietnam, JCS Memos, vol. I)
6. Document 13.
7. Document 27.
8. Appendix C to JCSM–811–65. [Footnote in the source text.]
9. Printed from a copy that indicates General Wheeler signed the original.