Declassified per Executive Order 13526, Section 3.3
NND Project Number: NND 63316. By: NWD Date: 2011
TOP SECRET – Sensitive
2. "Supplemental Note 2" to the paper, issued the day of the NSC meeting, contained, among other comments, a JCS estimate of the size of the American force needed "to clean up the Viet Cong threat." It reads:
Wider Military Implications. As the basic paper indicates, the likelihood of massive DRV and Chicom intervention can not be estimated with precision. The SNIE covers only the initial phase when action might be limited to 20-25,000 men. At later stages, when the JCS estimate that 40,000 US forces will be needed to clean up the Viet Cong threat, the chances of such massive intervention might well become substantial, with the Soviets finding it a good opportunity to tie down major US forces in a long action^ perhaps as part of a multi-prong action involving Berlin and such additional areas as Korea and Iran.
Because of this possibility of major Bloc intervention, the maximum possible force needs must be frankly faced. Assuming present estimates of about 40,000 US forces for the stated military objective in South Vietnam, plus 128,000 US forces for meeting North Vietnam and Chicom intervention, the drain on US-based reserve forces could be on the order of 3 or 4 divisions and other forces as well. The impact on naval capabilities for blockade plans (to meet Berlin) would also be major. In light of present Berlin contingency plans, and combat attrition, including scarce items of equipment, the initiation of the Vietnam action in itself should dictate a step up in the present mobilization, possibly of major proportions. 7/
Finally, there is the following memo from William Bundy (then acting Assistant Secretary of Defense, ISA) to McNamara. It is of interest because it is the only piece of paper available for this period that gives anyone's candid recommendations to his boss, as opposed to the more formal staff papers:
Even if the decision at tomorrow's meeting is only preliminary -- to explore with Diem and the British, Australians, and New Zealanders would be my guess -- it is clearly of the greatest possible importance. Above all, action must proceed fast.
For what one man's feel is worthy mine -- based on very close touch with Indochina in the 1954 war and civil war afterwards till Diem took hold -- is that it is is really now or never if we are to arrest the gains being made by the Viet Cong. Walt Rostow made the point yesterday that the Viet Cong are about to move, by every indication, from the small unit basis to a moderate battalion-size basis o Intelligence also suggests that they may try to set
