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

Dear Dean:

Pursuant to the National Policy Paper on South Africa,2 the Joint Chiefs of Staff have completed an analysis of the feasibility of using U.S. military forces as a part of a possible UN peace-keeping action, either to enforce a decision of the International Court of Justice regarding South West Africa or to enforce economic sanctions against South Africa. A copy of this analysis is attached.

The most significant factor in the Chiefs’ analysis involves the magnitude of forces which might be required. If the South African Government were to reach a decision to use force in resisting an adverse ICJ decision, the Chiefs believe that it would employ two light infantry divisions in South West Africa, keeping other South African units in reserve for the defense of South Africa proper. Against the units in South West Africa, the Chiefs consider that at least a four division force would be needed, at an overall force strength of about 160,000, supported by three wings of land-based aircraft and three carrier task forces. These forces would be supplemented by air and sea lift forces. Needless to say, if an action against South Africa proper were contemplated, considerably larger forces would be needed.

In the opinion of the Chiefs, the imposition of a naval blockade against South Africa alone would involve four carrier task forces, comprising four carriers, twenty-four destroyers and eight submarines on station. An extension of the blockade to the Angola and Mozambique coasts would entail an additional three carrier task force. The normal requirements of rotation, repair and the like would treble the overall number of ships if a blockade were maintained for an extended period.

The difficulties in mounting either military operation would be formidable. There would first be the task of finding the equivalent of four U.S. divisions that could fight together effectively against the forces of a modern, well-equipped and well-trained adversary. There would then follow the problems of organization, command, logistic support and other complexities associated with a military operation under international auspices. It is at least questionable whether the UK, France or any other of our NATO allies would contribute to either a land operation or a naval blockade and, as a result, the brunt of any Western contributions [Page 1026] would fall on the United States. The consequence would be an extremely costly diversion of U.S. forces.

In light of the above and other politico-military consequences which the Chiefs also note, they have strongly recommended against any military involvement in support of UN actions in southern Africa. I believe that you will find the Chiefs’ view particularly helpful in putting the dangers of such involvement in proper perspective. I am sending a copy of this letter to McGeorge Bundy.

Sincerely,

Bob
  1. Source: Department of State, S/P Files: Lot 72 D 139. Secret.
  2. Document 600.