Fermi and Szilard had both written reports on their secondary-neutron experiments and were ready to send them to the Physical Review. With Pegram’s concurrence they decided to go ahead and mail the reports to the Review, to establish priority, but to ask the editor to delay publishing them until the secrecy issue could be resolved...
...If Bohr could be convinced to swing his prestige behind secrecy, the campaign to isolate German nuclear physics research might work.
They met in the evening in Wigner’s office. “Szilard outlined the Columbia data,” Wheeler reports, “and the preliminary indications from it that at least two secondary neutrons emerge from each neutron-induced fission. Did this not mean that a nuclear explosive was certainly possible?” Not necessarily, Bohr countered. “We tried to convince him,” Teller writes, “that we should go ahead with fission research but we should not publish the results. We should keep the results secret, lest the Nazis learn of them and produce nuclear explosions first. Bohr insisted that we would never succeed in producing nuclear energy and he also insisted that secrecy must never be introduced into physics.”
...[Bohr] had worked for decades to shape physics into an international community, a model within its limited franchise of what a peaceful, politically united world might be. Openness was its fragile, essential charter, an operational necessity, as freedom of speech is an operational necessity to a democracy. Complete openness enforced absolute honesty: the scientist reported all his results, favorable and unfavorable, where all could read them, making possible the ongoing correction of error. Secrecy would revoke that charter and subordinate science as a political system—Polanyi’s “republic”—to the anarchic competition of the nation-states.
...March 17 was a Friday; Szilard traveled down to Washington from Princeton with Teller; Fermi stayed the weekend. They got together, reports Szilard, “to discuss whether or not these things”—the Physical Review papers—“should be published. Both Teller and I thought that they should not. Fermi thought that they should. But after a long discussion, Fermi took the position that after all this was a democracy; if the majority was against publication, he would abide by the wish of the majority.” Within a day or two the issue became moot. The group learned of the Joliot/von Halban/Kowarski paper, published in Nature on March 18. “From that moment on,” Szilard notes, “Fermi was adamant that withholding publication made no sense.”1135
[About a month later, German physicist] Paul Harteck wrote a letter jointly with his assistant to the German War Office: “We take the liberty of calling to your attention the newest development in nuclear physics, which, in our opinion, will probably make it possible to produce an explosive many orders of magnitude more powerful than the conventional ones… That country which first makes use of it has an unsurpassable advantage over the others.”
The Harteck letter reached Kurt Diebner, a competent nuclear physicist stuck unhappily in the Wehrmacht’s ordnance department studying high explosives. Diebner carried it to Hans Geiger. Geiger recommended pursuing the research. The War Office agreed.
Szilard told Einstein about the Columbia secondary neutron experiments and his calculations toward a chain reaction in uranium and graphite. Long afterward he would recall his surprise that Einstein had not yet heard of the possibility of a chain reaction. When he mentioned it Einstein interjected… “I never thought of that!” He was nevertheless, says Szilard, “very quick to see the implications and perfectly willing to do anything that needed to be done. He was willing to assume responsibility for sounding the alarm even though it was quite possible that the alarm might prove to be a false alarm. The one thing most scientists are really afraid of is to make fools of themselves. Einstein was free from such a fear and this above all is what made his position unique on this occasion.”
And:
By [August 1935] the Hungarians at least believed they saw major humanitarian benefit inherent in what Eugene Wigner would describe in retrospect as “a horrible military weapon,” explaining: “Although none of us spoke much about it to the authorities [during this early period] — they considered us dreamers enough as it was — we did hope for another effect of the development of atomic weapons in addition to the warding off of imminent disaster. We realized that, should atomic weapons be developed, no two nations would be able to live in peace with each other unless their military forces were controlled by a common higher authority. We expected that these controls, if they were effective enough to abolish atomic warfare, would be effective enough to abolish also all other forms of war. This hope was almost as strong a spur to our endeavors as was our fear of becoming the victims of the enemy’s atomic bombings.”
From the horrible weapon which they were about to urge the United States to develop, Szilard, Teller and Wigner — “the Hungarian conspiracy,” Merle Tuve was amused to call them — hoped for more than deterrence against German aggression. They also hoped for world government and world peace, conditions they imagined bombs made of uranium might enforce.
More (#1) from The Making of the Atomic Bomb:
On the origins of the Einstein–Szilárd letter:
And: