J. Robert Oppenheimer: General Advisory Committee Report on the Building of the H-Bomb

Explanation and Analysis of the Document

The first detonation of an atomic bomb by the Soviet Union took place on August 29, 1949. The signature of its radioactive fallout was immediately detected by the American military. The U.S. government commissioned a report from a panel of nuclear experts headed by Oppenheimer. Their report considered various options available to the United States in response to the new Soviet threat. One potential American response was to consider building a new kind of weapon referred to as the “super” in the jargon of atomic scientists and generally known as the hydrogen bomb. This device would not split heavy atoms apart, as did the fission process of the atomic bomb, but would combine together atoms of hydrogen (specifically the heavy isotope deuterium) into helium, re-creating the process that powers the sun. Oppenheimer's report makes it clear that a “characteristic of the super bomb is that once the problem of initiation” of the fusion reaction was solved, there would be “no limit to the explosive power of the bomb itself except that imposed by requirements of delivery.”

The atomic bombs dropped on Japan produced blasts equivalent to those of a few thousand tons of a conventional explosive like TNT. The explosive force produced by a hydrogen bomb is virtually unlimited. In practice, the largest explosive yield from such a device came in a Soviet test of a bomb whose force was equivalent to fifty million tons of TNT, more than all the conventional explosives that have ever been detonated in human history. Such an explosion could kill human beings sixty miles from its center and produce an enormous amount of radioactive fallout. Oppenheimer's report clearly anticipated the proposed bomb's power, stating that “it has generally been estimated that the weapon would have an explosive effect some hundreds of times that of present fission bombs. This would correspond to a damage area of the order of hundreds of square miles, to thermal radiation effects extending over a comparable area, and to very grave contamination problems.” The possession of such a weapon would seem to counter any threat posed by Soviet atomic weapons.

Oppenheimer, however, opposed production of the “super”—in the first instance, on moral grounds. Such a weapon could not be targeted exclusively on “installations of military or semi-military purposes.” As Oppenheimer's report phrases it, “Its use therefore carries much further than the atomic bomb itself the policy of exterminating civilian populations.” In his view even the possession of such a weapon constituted a threat of genocide, a morally unacceptable position to hold or to offer in the contest with the Soviets for the allegiance of other countries around the world. The committee's majority opinion, which Oppenheimer supported, warned that the use of a hydrogen bomb “would involve a decision to slaughter a vast number of civilians,” going on to voice alarm “as to the possible global effects of the radioactivity.” Thus “a super bomb might become a weapon of genocide.” Moreover, the mere “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 … represents a threat to the future of the human race which is intolerable.” For this reason, “the psychological effect of the weapon in our hands would be adverse to our interest.”

On the other hand, when this report was produced in 1949 it was not at all clear that the “super” was technically feasible. But it was certain that efforts to develop and test such a weapon would take resources away from the production of fission weapons whose destructive potential would be a credible deterrent against the Soviets even in the seemingly unlikely event that they developed a hydrogen bomb. Oppenheimer suggested that a better alternative would be to negotiate a ban, binding on both superpowers, on research into such weapons.

Other members of the General Advisory Committee, including the respected Enrico Fermi, took a much stronger stand than Oppenheimer, suggesting that the idea of making and using or threatening to use such a weapon was so morally evil that the United States should never pursue it, regardless of its technical feasibility or what the Soviets might do. In fact, once the work of the physicist Edward Teller in 1951 made it clear that a hydrogen bomb could be built, Oppenheimer reversed the position he had taken in the 1949 report, largely because he considered it inevitable that the Soviets (who showed no inclination to negotiate the matter) would eventually make one. Against the advice of the General Advisory Committee, work on the “super” went ahead. The first American hydrogen bomb was tested in 1952; the Soviets tested their first hydrogen bomb in 1955.