258. Letter From Secretary of Defense McNamara to the Administrator of the Agency for International Development (Hamilton)0

Dear Fowler: As you know, the Department of Defense has set up two major studies directed to the final decision on Korean force levels to be reached in accordance with NSC Action No. 2447.1

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One of these studies is a JCS analysis from a purely military standpoint.2 I expect to confer on this in the near future and will then forward it to you with my statement of the final Defense position. I am, however, attaching at this time the parallel study performed by a special group under Paul Nitze’s office, headed by Major General John B. Cary,USAF (Ret.), who was borrowed from the Institute of Defense Analyses for the purposes of this study.3 I am anxious that your staff review this study, on a limited circulation basis because of its sensitive nature, in order to be sure that we are not in any serious divergence concerning the economic analyses contained therein. It is also, of course, appropriate that you yourself should have this basic input to the total problem.

Paul Nitze’s office would welcome informal staff contact and comment either through him or directly to the action officer, Mr. Stephen Loftus.

I propose to proceed at this point by conferring with the JCS and with the interested parties in my office to arrive at a firm Defense Department position on this matter. I hope to do so early in May, and will then be in touch with you about the next steps to be taken.

Sincerely,

Bob4

Attachment

KOREA: A POLITICAL-MILITARY STUDY OF SOUTH KOREAN FORCES

[Here follow pages 1-35, which comprise sections I-VII: “Introduction,” “Underlying Factors,” “Political Environment,” “Economic Environment,” “Subversion and Insurgency,” “Military Environment,” and “Total Environment.”]

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VIII—Alternative Defense Policies

1. Of the many possible variations, three alternative defense policies were adopted for investigation. These are described in some detail in Annex M. They are summarized in the following paragraphs.

Option A

2. This option involves the provision of in-place forces in South Korea, which, together with available U.S. and ROK reinforcements, can contain, on a non-nuclear basis, an attack by North Korea alone. Since any major North Korean military operation requires Chinese Communist support and agreement, and at least tacit assent by the USSR, and since the Chinese have previously demonstrated their willingness to intervene if necessary to preserve North Korea as a Communist state, the question immediately arises as to what is necessary to keep the Chinese out. Since, under this assumed defense policy, it is not in-place military forces in South Korea, it follows that there must be some other military sanction available of sufficient strength and credibility to cause the Chinese to refrain from open intervention. This military sanction now exists. It is visible to the Chinese in the form of U.S. [less than 1 line of source text not declassified]forces now in the area.

Option C

3. This option is essentially the present defense policy of the U.S. with regard to South Korea—that is, to be able to contain, on a non-nuclear basis, open aggression by combined ChiCom/KorCom forces. [2 lines of source text not declassified]

Option B

4. This assumed defense policy is identical with Option C, except that it envisages immediate use [less than 1 line of source text not declassified] by the defending forces. It was assumed that the Chinese would retaliate with whatever indigenous [less than 1 line of source text not declassified] they might have after the U.S. initiated [less than 1 line of source text not declassified] operations. In view of the very few weapons estimated to be available to the Chinese, this assumption would result in one-sided use of [less than 1 line of source text not declassified] except for a very few, area-type weapons deliverable by Red China. (Section VI above)5

5. Sub-studies made by or for the Study Group clearly indicate that there would be an appreciable reduction in force requirements under this Option as compared with Option C. The Study Group was unable, however, to assess with any precision the impact of [3 lines of source text not declassified]. No further attention, therefore, has been devoted to this Option.

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General

6. In all three Options, it has been assumed that the mission of the defending forces is limited to containment of the initial Communist offensive. No geographic requirement is assumed except that there be retained sufficient depth to permit a further UN buildup if that should be necessary. It will be noted that this mission is somewhat at variance with the present mission of UN forces, which at least implies a requirement to retain Seoul, and which requires readiness to conduct a subsequent counter-offensive.

7. Two analytical sub-studies were made for the Study Group to serve as yardsticks for air and ground force requirements under Options A and C. Air considerations are covered in WSEG Staff Study No. 88 (available in draft form to the Study Group)6 which has been taken into consideration. A study limited to ground combat operations in the Korean environment is attached at Annex O.

8. Analyses of the two alternative defense policies follow in Sections IX and X. Option C is considered first, so that a situation which represents essentially the present defense policy can serve as a basis for analysis of change.

9. The methods used for these analyses are the product of the Study Group and do not represent either the methods of analysis nor the judgments of the responsible Commanders. It is emphasized that these analyses are based upon the large number of assumptions and estimates, some of a highly tenuous nature, set forth elsewhere in this study and particularly in Annex L. Even though the results of the analyses are set forth in direct terms, they are not intended and should not be construed to be of an absolute or categorical nature, since they are highly sensitive to the validity of the assumptions and estimates used.

[Here follow pages 39-55, which comprise sections IX “Option C,” X “Option A,” and XI “Implications of Major Force Reductions in ROK Forces.”

XII—Over-All Conclusion

1.
The Study Group, in comparing the two assumed defense policies (Options A and C) examined in this study, believes that Option A—if its adoption were linked to some highly significant and publicly evident change in the political or military situation, and if based on firm U.S. resolve to use its nuclear strength as necessary—would provide strong assurance that South Korea would not be attacked, and probably that it could not be successfully attacked. If it had been adopted earlier (in connection, [Page 562] say, with the withdrawal of Red Chinese forces from North Korea), political and economic advantage would probably have ensued.
2.
The Study Group considers that a reduction in ROK forces of the magnitude which would result from adoption of Option A, would, under present circumstances, entail risks and disadvantages which far outweigh any potential economic advantage which might ensue.
3.
Circumstances which would permit the early adoption of a defense policy entailing dramatic reductions in ROK military strength, without jeopardy to U.S. objectives and position, must include a prior, major improvement in the political and economic environments within South Korea, and additionally some visible political or military event at least approaching the significance of the ROK force reduction.
4.
The Study Group concludes, therefore, that the defense policy of the U.S. for the security of South Korea should not now undergo drastic revision and that the armed forces of the Republic of Korea should remain at approximately the level now programmed.

[Here follow 18 annexes.]

  1. Source: Washington National Records Center, RG 330, OSD Files: FRC 66 A 3542, Korea 320.2. Top Secret. Drafted by William Bundy on April 19.
  2. See Document 251.
  3. Document 254.
  4. As outlined in the introduction of the report the task of the study group under Cary was to determine the most desirable force posture for the ROK for 1962-1970. The group was specifically enjoined to consider possible alternative basic policies for the defense of Korea.
  5. Printed from a copy that indicates McNamara signed the original.
  6. Section VI was “Military Environment.”
  7. Apparent reference to “Some Aspects of Force Posture in Northeast Asia,” prepared by the Weapons Systems Evaluation Group (WSEG), April 25, and sent to the Director of Defense Research and Engineering on April 27. (Washington National Records Center, RG 330, OASD/ISA Files: FRC 66 A 3501, Korea 1962 320.2 (Cary Study))