Foreign Relations of the United States, 1964–1968, Volume X, National Security Policy

28. Memorandum From the President’s Special Assistant for National Security Affairs (Bundy) to President Johnson ¹

Washington, undated.

SUBJECT

• High Yield Nuclear Weapons

A year ago President Kennedy requested the Department of Defense and Atomic Energy Commission to re-examine the need for the development of very high yield nuclear weapons—particularly a weapon in the [less than 1 line of source text not declassified] category. He also requested a review of the question of developing a high yield warhead to be delivered by presently programmed missile systems.²

AEC and DOD have now recommended that we should not proceed with the development of a high yield weapon [less than 1 line of source text not declassified] for delivery by a B–52 bomber. The B–52 can now carry two [less than 1 line of source text not declassified] bombs, which bombs are already in the stockpile and are compatible with dual carriage in the B–52. There is [less than 1 line of source text not declassified] difference in the effectiveness between [less than 1 line of source text not declassified] bombs and one [less than 1 line of source text not declassified] bomb, and the expense of developing the [less than 1 line of source text not declassified] option is not warranted. They have also recommended that we should not develop a high yield warhead for present missiles. The additional expense is not justified by the increase in the capability of these missiles.

The memorandum³ also recommends that we should continue to conduct a vigorous program of research, experimentation, and underground testing directed toward the advancement of the state-of-the-art to the extent possible under the Limited Test Ban Treaty for the development of very high yield weapons of advanced design in the order of [less than 1 line of source text not declassified] or higher. The AEC is already pursuing this research objective without further authorization. The report also recommends that we improve our capability to test such large weapons in the atmosphere if the Treaty is broken. I believe this recommendation is justified and is consistent with the “safeguards” assurances we have given to the Congress and the terms of the partial test ban treaty.

If you approve, I will send the attached memorandum to Mr. Vance.⁴

McGeorge Bundy ⁵

1. Source:Johnson Library, National Security File, Memos to the President, McGeorge Bundy, Vol. 3. Top Secret; Restricted Data.
2. Regarding this review, see footnotes 3 and 5, Document 25.
3. Reference apparently is to an April 10 memorandum from Deputy Secretary of Defense Vance to President Johnson, which spelled out in some detail the reasons for opposing at that time development of high-yield nuclear weapons. (Washington National Records Center, OSD Files: FRC 330 69 A 7425, A–471.61 (25 Jan 64)) This memorandum incorporated almost all the proposed revisions suggested by the JCS in its Appendix to Document 25.
4. Not attached, but printed as Document 29.
5. Printed from a copy that bears this typed signature.