227. Memorandum From the Secretary of Defense (McNamara) to the President1


  • South Vietnam

The basic issue framed by the Taylor Report is whether the U.S. shall:

Commit itself to the clear objective of preventing the fall of South Viet-Nam to Communism,2 and
Support this commitment by necessary immediate military actions and preparations for possible later actions.

The Joint Chiefs, Mr. Gilpatric, and I have reached the following conclusions: [Page 560]

The fall of South Viet-Nam to Communism would lead to the fairly rapid extension of Communist control, or complete accommodation to Communism, in the rest of mainland Southeast Asia and in Indonesia. The strategic implications worldwide, particularly in the Orient, would be extremely serious.
The chances are against, probably sharply against, preventing that fall by any measures short of the introduction of U.S. forces on a substantial scale. We accept General Taylor’s judgment that the various measures proposed by him short of this are useful but will not in themselves do the job of restoring confidence and setting Diem on the way to winning his fight.
The introduction of a U.S. force of the magnitude of an initial 8,000 men in a flood relief context will be of great help to Diem. However, it will not convince the other side (whether the shots are called from Moscow, Peiping, or Hanoi) that we mean business. Moreover, it probably will not tip the scales decisively. We would be almost certain to get increasingly mired down in an inconclusive struggle.
The other side can be convinced we mean business only if we accompany the initial force introduction by a clear commitment to the full objective stated above, accompanied by a warning through some channel to Hanoi that continued support of the Viet Cong will lead to punitive retaliation against North Vietnam.
If we act in this way, the ultimate possible extent of our military commitment must be faced. The struggle may be prolonged and Hanoi and Peiping may intervene overtly. In view of the 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 32-59,3 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.
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 [Page 561] Moscow and Peiping will need careful weighing and may well be mixed; however, permitting South Viet-Nam to fall can only strengthen and encourage them greatly.
In sum:
We do not believe major units of U.S. forces should be introduced into South Viet-Nam unless we are willing to make an affirmative decision on the issue stated at the start of this memorandum.
We are inclined to recommend that we do commit the U.S. to the clear objective of preventing the fall of South Viet-Nam to Communism and that we support this commitment by the necessary military actions.
If such a commitment is agreed upon, we support the recommendations of General Taylor as the first steps toward its fulfillment.

Robert S. McNamara
  1. Source: Washington National Records Center, RG 330, McNamara Files: FRC 71 A 3470, SE Asia 1961. Top Secret. Also printed in United States-Vietnam Relations, 1945-1967, Book 11, pp. 343-344.
  2. On a November 7 draft of this memorandum, the following words were crossed out at this point: “thus holding the non-Communist areas of Southeast Asia,”. (Department of State, Central Files, 611.51K/11-761) This is the only difference between the November 7 draft and the source text.
  3. Not found.