In August 1949 the Soviet Union exploded its first atomic bomb, ending the American monopoly on nuclear weapons. Their test triggered a secret debate within the U.S. government over whether to undertake an “all-out” effort to build a “super bomb” that would use the immense heat of a fission (atomic) bomb to ignite fusion reactions in isotopes of hydrogen. Although scientists had known since 1942 that a hydrogen bomb was theoretically possible, after seven years it was still unclear whether building one was technically feasible. At the end of October 1949 the General Advisory Committee of the Atomic Energy Commission met in Washington to debate “the super” over the course of a three-day meeting. Led by J. Robert Oppenheimer, the GAC was made up of leading scientists and scientific administrators, many of whom had played major roles in the wartime atomic bomb project. (Oppenheimer had watched the first detonation of an atomic bomb, on July 16, 1945, in New Mexico; thinking back on the experience later, he said that on seeing the detonation he recalled Lord Krishna’s declaration in the Bhagavad Gita, “Now I am become Death, the destroyer of worlds.”)
After three days of deliberations, the committee unanimously recommended against pursuing the hydrogen bomb for reasons both technical—set forth in the main committee report—and moral, as expressed in the report’s majority and minority annexes. The protests of the GAC scientists fell on deaf ears, and in January 1950 President Truman ordered work on the hydrogen bomb to proceed. A series of theoretical breakthroughs in 1951 made the bomb feasible, and the initial test of the new design concept in November 1952 released almost 700 times the energy of the weapon dropped on Hiroshima. Soviet scientists raced to catch up, and in November 1955 successfully exploded their own hydrogen super bomb.
October 30, 1949
WE have been asked by the Commission whether or not they should immediately initiate an “all-out” effort to develop a weapon whose 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 hopes of mankind.
James B. Conant
Hartley Rowe
Cyril Stanley Smith
L. A. DuBridge
Oliver E. Buckley
J. R. Oppenheimer
October 30, 1949
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 practical 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, 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. FERMI
I. I. RABI