PM Files1

The Chairman of the General Advisory Committee ( Oppenheimer ) to the Chairman of the United States Atomic Energy Commission ( Lilienthal )

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Dear Mr. Lilienthal: At the request of the Commission, the seventeenth meeting of the General Advisory Committee was held in Washington on October 29 and 30, 1949 to consider some aspects of the [Page 570] question of whether the Commission was making all appropriate progress in assuring the common defense and security.2 Dr. Seaborg’s3 absence in Europe prevented his attending this meeting. For purposes of background, the Committee met with the Counsellor of the State Department, with Dr. Henderson of AEC Intelligence, with the Chairman of the Joint Chiefs of Staff, the Chairman of the Military Liaison Committee, the Chairman of the Weapons Systems Evaluation Group, General Norstadt and Admiral Parsons.4 In addition, as you know, we have had intimate consultations with the Commission itself.

The report which follows falls into two parts. The first describes certain recommendations for action by the Commission directed toward the common defense and security. The second is an account of the nature of the super project and of the super as a weapon, together with certain comments on which the Committee is unanimously agreed.5 Attached to the report, but not a part of it, are recommendations with regard to action on the super project which reflect the opinions of Committee members.

The Committee plans to hold its eighteenth meeting in the city of Washington on December 1, 2 and 3, 1949. At that time we hope to return to many of the questions which we could not deal with at this meeting.

J. R[obert] Oppenheimer
[Enclosure 1]

Statement Appended to the Report of the General Advisory Committee 6

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We have been asked by the Commission whether or not they should immediately initiate an “all-out” effort to develop a weapon whose [Page 571] energy release is 100 to 1000 times greater and whose destructive power in terms of area of damage is 20 to 100 times greater than those of the present atomic bomb. We recommend strongly against such action.

We base our recommendation on our belief that the extreme dangers to mankind inherent in the proposal wholly outweigh any military advantage that could come from this development. Let it be clearly realized that this is a super weapon; it is in a totally different category from an atomic bomb. The reason for developing such super bombs would be to have the capacity to devastate a vast area with a single bomb. Its use would involve a decision to slaughter a vast number of civilians. We are alarmed as to the possible global effects of the radioactivity generated by the explosion of a few super bombs of conceivable magnitude. If super bombs will work at all, there is no inherent limit in the destructive power that may be attained with them. Therefore, a super bomb might become a weapon of genocide.

The existence of such a weapon in our armory would have far-reaching effects on world opinion: reasonable people the world over would realize that the existence of a weapon of this type whose power of destruction is essentially unlimited represents a threat to the future of the human race which is intolerable. Thus we believe that the psychological effect of the weapon in our hands would be adverse to our interest.

We believe a super bomb should never be produced. Mankind would be far better off not to have a demonstration of the feasibility of such a weapon until the present climate of world opinion changes.

It is by no means certain that the weapon can be developed at all and by no means certain that the Russians will produce one within a decade. To the argument that the Russians may succeed in developing this weapon, we would reply that our undertaking it will not prove a deterrent to them. Should they use the weapon against us, reprisals by our large stock of atomic bombs would be comparably effective to the use of a super.

In determining not to proceed to develop the super bomb, we see a unique opportunity of providing by example some limitations on the totality of war and thus of limiting the fear and arousing the hope of mankind.

  • James B. Conant
  • Hartley Rowe
  • Cyril Stanley Smith
  • L[ee] A. DuBridge
  • Oliver E. Buckley
  • J. R[obert] Oppenheimer
[Page 572]
[Enclosure 2]

Statement Appended to the Report of the General Advisory Committee 7

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An Opinion on the Development of the “Super

A decision on the proposal that an all-out effort be undertaken for the development of the “Super” cannot in our opinion be separated from considerations of broad national policy. A weapon like the “Super” is only an advantage when its energy release is from 100–1000 times greater than that of ordinary atomic bombs. The area of destruction therefore would run from 150 to approximately 1000 square miles or more.

Necessarily such a weapon goes far beyond any military objective and enters the range of very great natural catastrophes. By its very nature it cannot be confined to a military objective but becomes a weapon which in pratical effect is almost one of genocide.

It is clear that the use of such a weapon cannot be justified on any ethical ground which gives a human being a certain individuality and dignity even if he happens to be a resident of an enemy country. It is evident to us that this would be the view of peoples in other countries. Its use would put the United States in a bad moral position relative to the peoples of the world.

Any postwar situation resulting from such a weapon would leave unresolvable enmities for generations. A desirable peace cannot come from such an inhuman application of force. The postwar problems would dwarf the problems which confront us at present.

The application of this weapon with the consequent great release of radioactivity would have results unforeseeable at present, but would certainly render large areas unfit for habitation for long periods of time.

The fact that no limits exist to the destructiveness of this weapon makes its very existence and the knowledge of its construction a danger to humanity as a whole. It is necessarily an evil thing considered in any light.

For these reasons we believe it important for the President of the United States to tell the American public, and the world, that we think it wrong on fundamental ethical principles to initiate a program of development of such a weapon. At the same time it would be appropriate to invite the nations of the world to join us in a solemn pledge not to proceed in the development or construction of weapons of this category. If such a pledge were accepted even without control machinery, [Page 573] it appears highly probable that an advanced stage of development leading to a test by another power could be detected by available physical means. Furthermore, we have in our possession, in our stockpile of atomic bombs, the means for adequate “military” retaliation for the production or use of a “Super”.

  • E[nrico] Fermi
  • I[sidor] I. Rabi
  1. Files retained by the Bureau of Politico-Military Affairs, Department of State.
  2. Consideration of this subject by the United States Atomic Energy Commission and its General Advisory Committee during late September and October included discussion of the possibility of developing thermonuclear weapons. These deliberations are described in Hewlett and Duncan, pp. 369–388. For additional information on consideration of the hydrogen bomb question during late 1949 and early 1950, see R. Gordon Arneson, “The H-Bomb Decision,” Foreign Service Journal, May 1969, p. 27, and June 1969, p. 24, and the U.S. Atomic Energy Commission, In the Matter of J. Robert Oppenheimer: Transcript of Hearing before Personnel Security Board, Washington, D.C., April 12, 1954–May 6, 1954 (Washington: Government Printing Office, 1954).
  3. Dr. Glenn T. Seaborg, Member of the General Assembly Committee, United States Atomic Energy Commission.
  4. Rear Adm. William S. Parsons, Member of the Military Liaison Committee to the U.S. Atomic Energy Commission.
  5. The report of the General Advisory Committee is not printed. Its first part urged increased production of fissionable material. The second part recommended against the high-priority development of thermonuclear weapons. The report is further described in Hewlett and Duncan, pp. 383385.
  6. Regarding the report itself, see footnote 5, above.
  7. Regarding the report itself, see footnote 5, p. 570.