292. Letter From Secretary of Defense McNamara to Secretary of State Rusk1

Dear Dean:

You will of course recall the request made to you by Thai Foreign Minister Thanat at Manila last year that U.S. command arrangements in Southeast Asia be modified.

I have noted the political problems repeatedly expressed by Ambassador Martin and the long-standing sensitivity of the Thai Government to the double-hat COMUSMACV/COMUSMACTHAI arrangement.2 Weighing equally in my view is the requirement to promote efficiency in current operations in the RVN by enabling COMUSMACV to concentrate his efforts on the immediate task of defeating the Viet Cong. Accordingly, I have decided upon the separation of the subordinate unified commands, COMUSMACV and COMUSMACTHAI, and the assignment of an Army Major General as COMUSMACTHAI/CHJUSMAAGTHAI and an Air Force Brigadier General as Chief of Staff, MACTHAI.

At the same time, the Joint Chiefs of Staff recognize that the planning responsibilities borne by COMUSMACV as Commander, U.S. Forces Southeast Asia (COMUSSEASIA) (designate) and as Commander, Central Region SEATO Field Forces (COMCRSFF) (designate) require that he be in a position to exercise policy control over the SEASIA and SEATO planning activities undertaken by COMUSMACTHAI.3 This control, I believe, should be exercised through a direct U.S. channel to be kept open between COMUSMACTHAI and General Westmoreland, as COMUSSEASIA (designate) and as COMCRSFF (designate). Accordingly, for staff support to accomplish the SEASIA and SEATO planning functions, the present small COMUSMACTHAI planning group at Bangkok should be augmented. Additionally, a communications and operations facility should be developed at Korat, Thailand, to permit a possible later expansion into a headquarters for COMUSSEA and COMCRSFF. You may wish to notify the Thai Government of this proposed change at the SEATO meeting in London next week.


RM 4
  1. Source: Department of State, S/S-Conference Files: Lot 66 D 347, 10th SEATO Meeting, CF 2498. Top Secret.
  2. Martin made this point most recently in telegram 1456 from Bangkok, March 31, and recommended the command structure outlined by McNamara in this letter. Martin stated that the structure “would be completely acceptable” to the Thai Government. (Ibid., Central Files, POL 27 VIET S)
  3. As stated in a memorandum from the JCS to McNamara, JCSM–319–65, April 28. (Department of Defense, JCS Official Files, 9150 (28 Apr 65)
  4. Pinted from a copy that bears these taped initials.