Among the many things changed by the advent of nuclear weapons was the nature of war resistance. Some who had no quarrel with the war against Germany and Japan took a stand against the use of such weapons, which seemed to alter war itself, threatening utter annihilation. Among the first of these antinuclear activists were some of the scientists who had conceived of nuclear weapons in the first place and participated in their development. Better able than most military and civilian leaders to imagine the destruction these weapons were capable of, and to foresee the consequences of nuclear conflict, they sought to prevent the first use of the terrible power they had helped to unleash.
Leo Szilard (1898–1964) was a leader of these scientists. Born in Budapest, he emigrated to Germany in 1919, studying physics at the University of Berlin; among his teachers was Albert Einstein, with whom he developed and patented the “Einstein-Szilard refrigerator.” In 1933 he fled Nazi Germany and went to England, where he first realized the military potential of a multiplying neutron chain reaction. He came to the United States in 1938—collaborating with Einstein on an August 1939 letter warning President Roosevelt of the potential of “extremely powerful bombs of a new type”—and became a citizen in 1943. He played a significant role in the development of the first nuclear reactors, though he often found himself at odds with the military men who took over his research work.
In early July 1945—just over a month before the atomic bomb was dropped on Hiroshima—Szilard circulated the letter and petition reprinted below among his colleagues on the Manhattan Project. Slightly revised, it went to President Truman bearing seventy signatures, but it did not make it up the chain of command in time for Truman to see it before the destruction of Hiroshima and Nagasaki.
After the war Szilard turned his research from nuclear physics to molecular biology. He persisted in his opposition to the proliferation of nuclear weapons, publicly opposing the development of the hydrogen bomb and founding the Council for Abolishing War (now the Council for a Livable World) in 1962.
July 4, 1945
Dear
Inclosed is the text of a petition which will be submitted to the President of the United States. As you will see, this petition is based on purely moral considerations.
It may very well be that the decision of the President whether or not to use atomic bombs in the war against Japan will largely be based on considerations of expediency. On the basis of expediency, many arguments could be put forward both for and against our use of atomic bombs against Japan. Such arguments could be considered only within the framework of a thorough analysis of the situation which will face the United States after this war and it was felt that no useful purpose would be served by considering arguments of expediency in a short petition.
However small the chance might be that our petition may influence the course of events, I personally feel that it would be a matter of importance if a large number of scientists who have worked in this field went clearly and unmistakably on record as to their opposition on moral grounds to the use of these bombs in the present phase of the war.
Many of us are inclined to say that individual Germans share the guilt for the acts which Germany committed during this war because they did not raise their voices in protest against those acts. Their defense that their protest would have been of no avail hardly seems acceptable even though these Germans could not have protests without running risks to life and liberty. We are in a position to raise our voices without incurring any such risks even though we might incur the displeasure of some of those who are at present in charge of controlling the work on “atomic power.”
The fact that the people of the United States are unaware of the choice which faces us increases our responsibility in this matter since those who have worked on “atomic power” represent a sample of the population and they alone are in a position to form an opinion and declare their stand.
Anyone who might wish to go on record by signing the petition ought to have an opportunity to do so and, therefore, it would be appreciated if you could give every member of your group an opportunity for signing.
Leo Szilard
P.S.—Anyone who wants to sign the petition ought to sign both attached copies and ought to read not only the petition but also this covering letter.
July 3, 1945
Discoveries of which the people of the United States are not aware may affect the welfare of this nation in the near future. The liberation of atomic power which has been achieved places atomic bombs in the hands of the Army. It places in your hands, as Commander-in-Chief, the fateful decision whether or not to sanction the use of such bombs in the present phase of the war against Japan.
We, the undersigned scientists, have been working in the field of atomic power for a number of years. Until recently we have had to reckon with the possibility that the United States might be attacked by atomic bombs during this war and that her only defense might lie in a counterattack by the same means. Today with this danger averted we feel impelled to say what follows:
The war has to be brought speedily to a successful conclusion and the destruction of Japanese cities by means of atomic bombs may very well be an effective method of warfare. We feel, however, that such an attack on Japan could not be justified in the present circumstances. We believe that the United States ought not to resort to the use of atomic bombs in the present phase of the war, at least not unless the terms which will be imposed upon Japan after the war are publicly announced and subsequently Japan is given an opportunity to surrender.
If such public announcement gave assurance to the Japanese that they could look forward to a life devoted to peaceful pursuits in their homeland and if Japan still refused to surrender, our nation would then be faced with a situation which might require a re-examination of her position with respect to the use of atomic bombs in the war.
Atomic bombs are primarily a means for the ruthless annihilation of cities. Once they were introduced as an instrument of war it would be difficult to resist for long the temptation of putting them to such use.
The last few years show a marked tendency toward increasing ruthlessness. At present our Air Forces, striking at the Japanese cities, are using the same methods of warfare which were condemned by American public opinion only a few years ago when applied by the Germans to the cities of England. Our use of atomic bombs in this war would carry the world a long way further on this path of ruthlessness.
Atomic power will provide the nations with new means of destruction. The atomic bombs at our disposal represent only the first step in this direction and there is almost no limit to the destructive power which will become available in the course of this development. Thus a nation which sets the precedent of using these newly liberated forces of nature for purposes of destruction may have to bear the responsibility of opening the door to an era of devastation on an unimaginable scale.
In view of the foregoing, we, the undersigned, respectfully petition that you exercise your power as Commander-in-Chief to rule that the United States shall not, in the present phase of the war, resort to the use of atomic bombs.