Declassified per Executive Order 13526, Section 3.3
NND Project Number: NND 63316. By: NWD Date: 2011
TOP SECRET – Sensitive
logistic difficulties faced by the other side, I believe we can assume that the maximum U.S. forces required on the ground in Southeast Asia will not exceed 6 divisions, or about 205,000 men (CINCPAC Plan 32-59, Phase IV) . Our military posture is, or with the addition of more National Guard or regular Army divisions, can be made, adequate to furnish these forces without serious interference with our present Berlin plans.
6. To accept the stated objective is of course a most serious decision. Military force is not the only element of what must be a most carefully coordinated set of actions. Success will depend on factors many of which are not within our control -- notably the conduct of Diem himself and other leaders in the area. Laos will remain a major problem. The domestic political implications of accepting the objective are also grave, although it is our feeling that the country will respond better to a firm initial position than to courses of action that lead us in only gradually, and that in the meantime are sure to involve casualties. The over-all effect on Moscow and Peiping will need careful weighing and may well be mixed; however, permitting South Vietnam to fall can only strengthen and encourage them greatly.
7. In sum:
a. We do not believe major units of U.S. forces should be introduced in South Vietnam unless we are willing to make an affirmative decision on the issue stated at the start of this memorandum.
b. We are inclined to recommend that we do commit the U.S. to the clear objective of preventing the fall of South Vietnam to Communism and that we support this commitment by the necessary military actions.
c. If such a commitment is agreed upon, we support the recommendations of General Taylor as the first steps toward its fulfillment.
Sgd: Robert S. McNamara 16/
A number of things are striking about this memorandum, including of course the judgment that the "maximum" U.S. ground forces required, even in the case of overt intervention by not only North Vietnam, but China as well, would "not exceed" 205,000 men. This estimate of the requirement to deal with a large scale overt invasion is consistent with the Chief's earlier estimate that the addition of 40,000 U.S. troops to the South Vietnamese forces would be sufficient to "clean up" the Viet Cong.
But the strongest message to the President in the memorandum (growing out of points 3, 4, and 7c) was surely that if he agreed to sending the military task force, he should be prepared for follow-up recommendations
