The two letters of Leo Szilard


One month prior to the start of World War II, an atomic scientist named Leo Szilard convinced Albert Einstein to send the following letter to the U. S. President Franklin Delano Roosevelt (Franklin D. Roosevelt Presidential Library and Museum - National Archives, Hyde Park, New York):

"Albert Einstein"

"Old Grove Rd."

"Nassau Point"

"Peconic, Long Island"

"August 2nd, 1939"

"F. D. Roosevelt,"

"President of the United States,"

"White House"

"Washington, D.C."


"Some recent work by E.Fermi and L. Szilard, which has been communicated to me in manuscript, leads me to expect that the element uranium may be turned into a new and important source of energy in the immediate future. Certain aspects of the situation which has arisen seem to call for watchfulness and, if necessary, quick action on the part of the Administration. I believe therefore that it is my duty to bring to your attention the following facts and recommendations:"

"In the course of the last four months it has been made probable - through the work of Joliot in France as well as Fermi and Szilard in America - that it may become possible to set up a nuclear chain reaction in a large mass of uranium,by which vast amounts of power and large quantities of new radium-like elements would be generated. Now it appears almost certain that this could be achieved in the immediate future."

"This new phenomenon would also lead to the construction of bombs, and it is conceivable - though much less certain - that extremely powerful bombs of a new type may thus be constructed. A single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory. However, such bombs might very well prove to be too heavy for transportation by air."

"The United States has only very poor ores of uranium in moderate quantities. There is some good ore in Canada and the former Czechoslovakia, while the most important source of uranium is Belgian Congo."

"In view of this situation you may think it desirable to have some permanent contact maintained between the Administration and the group of physicists working on chain reactions in America. One possible way of achieving this might be for you to entrust with this task a person who has your confidence and who could perhaps serve in an inofficial capacity. His task might comprise the following:"

"a) to approach Government Departments, keep them informed of the further development, and put forward recommendations for Government action, giving particular attention to the problem of securing a supply of uranium ore for the United States;"

"b) to speed up the experimental work,which is at present being carried on within the limits of the budgets of University laboratories, by providing funds, if such funds be required, through his contacts with private persons who are willing to make contributions for this cause, and perhaps also by obtaining the co-operation of industrial laboratories which have the necessary equipment."

"I understand that Germany has actually stopped the sale of uranium from the Czechoslovakian mines which she has taken over. That she should have taken such early action might perhaps be understood on the ground that the son of the German Under-Secretary of State, von Weizsacker, is attached to the Kaiser-Wilhelm-Institut in Berlin where some of the American work on uranium is now being repeated."

"Yours very truly,"

"(Albert Einstein)"

One month prior to the end of World War II, the same atomic scientist Leo Szilard convinced 69 other atomic scientists to send the following letter to the U. S. President Harry S Truman (The Harry S. Truman Library and Museum - National Archives and Records Administration, Independence, Missouri):

"July 17, 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. Until recently we have had to fear 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 the defeat of Germany, this danger is averted and we feel impelled to say what follows:"

"The war has to be brought speedily to a successful conclusion and attacks by atomic bombs may very well be an effective method of warfare. We feel, however, that such attacks on Japan could not be justified, at least not unless the terms which will be imposed after the war on Japan were made public in detail and Japan were 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 might then, in certain circumstances, find itself forced to resort to the use of atomic bombs. Such a step, however, ought not to be made at any time without seriously considering the moral responsibilities which are involved."

"The development of 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 their future 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."

"If after this war a situation is allowed to develop in the world which permits rival powers to be in uncontrolled possession of these new means of destruction, the cities of the United States as well as the cities of other nations will be in continuous danger of sudden annihilation. All the resources of the United States, moral and material, may have to be mobilized to prevent the advent of such a world situation. Its prevention is at present the solemn responsibility of the United States--singled out by virtue of her lead in the field of atomic power."

"The added material strength which this lead gives to the United States brings with it the obligation of restraint and if we were to violate this obligation our moral position would be weakened in the eyes of the world and in our own eyes. It would then be more difficult for us to live up to our responsibility of bringing the unloosened forces of destruction under control."

"In view of the foregoing, we, the undersigned, respectfully petition: first, that you exercise your power as Commander-in-Chief, to rule that the United States shall not resort to the use of atomic bombs in this war unless the terms which will be imposed upon Japan have been made public in detail and Japan knowing these terms has refused to surrender; second, that in such an event the question whether or not to use atomic bombs be decided by you in the light of the considerations presented in this petition as well as all the other moral responsibilities which are involved."

"(Leo Szilard and 69 more co-signers)"

Both letters, drafted by the same individual (Szilard), under the same circumstances (War) and for the same reasons (defending Freedom against Totalitarianism), speak for themselves. Both letters continue to be relevant into the 21st Century.

Aldo Loup.

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Photograph: "Gadget", the first atom bomb, before the detonators were installed by Dr. Norris Bradbury, atop a tower in the Jornada del Muerto ("Journey of the Death") desert, Alamogordo Bombing and Gunnery Range, New Mexico, for the "Trinity" test, which took place shortly thereafter at 5:29:45 Mountain War Time on 16 July 1945, unleashing the "Pandora's Box" of nuclear terror over planet Earth. After installing the detonators the night before that fateful date, Dr. Bradbury made an annotation in his log book: "Look for rabbit's feet and four leaf clovers. Should we have the chaplain down here?" Photo credit: U. S. Army Corps of Engineers "Manhattan Engineer District", now better known by its true identity as the top secret U. S. Armed Forces "Manhattan Project", which developed the Atom Bomb at a cost of US$ 2 billion from 1942 to 1945, and is regarded as the greatest concentration of the world's most brilliant scientists in the history of Homo sapiens.