Summary of Secretary of Defense Robert S. McNamara's Memo to President Johnson, July 20, 1965
Secretary McNamara's 20 July 1965 Memorandum for the President [Doc. 261] spelled out the troop requirements for Vietnam as follows: The forces for 1965 should be brought up to about 175,000, and "It should be understood that the deployment of more men (perhaps 100,000) may be necessary in early 1966, and the deployment of additional forces thereafter is possible but will depend on developments."
This 100,000-man possible addition was broken down in a cable from COMUSMACV to CINCPAC as providing 27 maneuver battalions with associated battalions to 61 sometime in 1966. The question arises as to how this 100,000 man 27-battalion figure was reached. In the absence of documentary evidence, it seems simplest to assume that Westmoreland was given pretty much what he asked for. However, the 61 battalion figure comes very close to the number of battalions the Secretary of Defense was thinking about earlier in July, when a memorandum for the record dated 12 July shows a proposal to strengthen U.S. forces by 63 battalions through a combination of calling up reserves, extending tours of duty, and increasing the draft. In fact, the 63 battalion figure appears again in the Secretary's 20 July memorandum to the President, allowing one to speculate that the size of the build-up had already been fixed in early July prior to the trip.
In either case, the result was that Phase II was recommended to the President at a level of roughly 100,000 which when added to the then current estimates for Phase I of 175,000 gave a total estimate of 275,000 by the end of 1966. Secretary McNamara envisioned that the employment of U.S. forces would be as follows:
. . . Use of forces.The forces will be used however they can be brought to bear most effectively. The U.S. third-country ground forces will operate in coordination with South Vietnamese forces. They will defend their own bases; they will assist in providing security in neighboring areas; they will augment Vietnamese forces, assuring retention of key logistic areas and population centers. Also, in the initial phase they will maintain a small reserve-reaction force, conducting nuisance raids and spoiling attacks, and opening and securing selected lines of communication; as in-country ground strength increases to a level permitting extended U.S. and third-country offensive action, the forces will be available for more active combat missions when the Vietnamese Government and General Westmoreland agree that such active missions are needed. The strategy for winning this stage of the war will be to take the offensive to take and hold the initiative. The concept of tactical operations will be to exploit the offensive, with the objects of putting the VCIDRV battalion forces out of operation and of destroying their morale. The South Vietnamese, U.S. and third-country forces, by aggressive exploitation of superior military forces, are to gain and hold the initiative keeping the enemy at a disadvantage, maintaining a tempo such as to deny them time to recuperate or regain their balance, and pressing the fight against VCIDRV main force units in South Vietnam to run them to ground and to destroy them. The operations should combine to compel the VCIDRV to fight at a higher and more sustained intensity with resulting higher logistical consumption and, at the same time, to limit his capability to resupply forces in combat at that scale by attacking his LOC. The concept assumes vigorous prosecution of the air and sea anti-infiltration campaign and includes increased use of air in-country, including B-52s, night and day to harass VC in their havens. Following destruction of the VC main force units, the South Vietnamese must reinstitute the Program of Rural Reconstruction as an antidote to the continuing VC campaign of terror and subversion.
. . . Evaluation. ARVN overall is not capable of successfully resisting the VC initiatives without more active assistance from more U.S. third-country ground forces than those thus far committed. Without further outside help, the ARVN is faced with successive tactical reverses, loss of key communication and population centers particularly in the highlands, piecemeal destruction of ARVN units, attrition of RVNAF will to fight, and loss of civilian confidence. Early commitment of additional U.S. third-country forces in sufficient quantity, in general reserve and offensive roles, should stave off GVN defeat.
The success of the program from the military point of view turns on whether the Vietnamese hold their own in terms of numbers and fighting spirit, and on whether the U.S. forces can be effective in a quick-reaction reserve role, a role in which they are only now being tested. The number of U.S. troops is too small to make a significant difference in the tradition 10-1 government-guerrilla formula, but it is not too small to make a significant difference in the kind of war which seems to be evolving in Vietnam a "Third Stage" or conventional war in which it is easier to identify, locate and attack the enemy.
The plan is such that the risk of escalation into war with China or the Soviet Union can be kept small. U.S. and South Vietnamese casualties will increase just how much cannot be predicted with confidence, but the U.S. killed-in-action might be in the vicinity of 500 a month by the end of the year. The South Vietnamese under one government or another will probably see the thing through and the United States public will support the course of action because it is a sensible and courageous military-political program designed and likely to bring about a success in Vietnam.
It should be recognized, however, that success against the larger, more conventional, VCIPAVN forces could merely drive the VC back into the trees and back to their 1960-64 pattern a pattern against which U.S. troops and aircraft would be of limited value but with which the GVN, with our help, could cope. The questions here would be whether the VC could maintain morale after such a setback, and whether the South Vietnamese would have the will to hang on through another cycle.
SOURCE: Gravel (ed.), Pentagon Papers, Vol. 4, pp.297-299.