Albert Einstein and the Problem of War
By Lawrence Wittner
Reposted from the Peace and Health Blog of the International Physicians for the Prevention of Nuclear War (https://peaceandhealthblog.com/2025/10/11/albert-einstein-and-the-problem-of-war/)
Although Albert Einstein is best-known as a theoretical physicist, he also spent much of his life grappling with the problem of war. In 1914, shortly after he moved to Berlin to serve as director of the Kaiser Wilhelm Institute of Physics, Einstein was horrified by the onset of World War I. “Europe, in her insanity, has started something unbelievable,” he told a friend. “In such times one realizes to what a sad species of animal one belongs.” Writing to the French author Romain Rolland, he wondered whether “centuries of painstaking cultural effort” have “carried us no further than . . . the insanity of nationalism.”
As militarist propaganda swept through Germany, accompanied that fall by a heated patriotic “Manifesto” from 93 prominent German intellectuals, Einstein teamed up with the German pacifist Georg Friedrich Nicolai to draft an antiwar response, the “Manifesto to Europeans.” Condemning “this barbarous war” and the “hostile spirit” of its intellectual apologists, the Einstein-Nicolai statement maintained that “nationalist passions cannot excuse this attitude which is unworthy of what the world has heretofore called culture.”
In the context of the war’s growing destructiveness, Einstein also helped launch and promote a new German antiwar organization, the New Fatherland League, which called for a prompt peace without annexations and the formation of a world government to make future wars impossible. It engaged in petitioning the Reichstag, challenging proposals for territorial gain, and distributing statements by British pacifists. In response, the German government harassed the League and, in 1916, formally suppressed it.
After the World War came to an end, Einstein became one of the Weimar Republic’s most influential pacifists and internationalists. Despite venomous attacks by Germany’s rightwing nationalists, he grew increasingly outspoken. “I believe the world has had enough of war,” he told an American journalist. “Some sort of international agreement must be reached among nations.” Meanwhile, he promoted organized war resistance, denounced military conscription, and, in 1932, drew Sigmund Freud into a famous exchange of letters, later published as Why War.
Although technically a Zionist, Einstein had a rather relaxed view of that term, contending that it meant a respect for Jewish rights around the world. Appalled by Palestinian-Jewish violence in British-ruled Palestine, he pleaded for cooperation between the two constituencies. In 1938, he declared that he would “much rather see reasonable agreement with the Arabs on the basis of living together in peace than the creation of a Jewish state.” He disliked “the idea of a Jewish state with borders, an army, and a measure of temporal power,” plus “the development of a narrow nationalism within our own ranks.”
The most serious challenge to Einstein’s pacifism came with the Nazi takeover of Germany in 1933 and the advent of that nation’s imperialist juggernaut. “My views have not changed,” he told a French pacifist, “but the European situation has.” As long as “Germany persists in rearming and systematically indoctrinating its citizens in preparation for a war of revenge, the nations of Western Europe depend, unfortunately, on military defense.” In his heart, he said, he continued to “loathe violence and militarism as much as ever; but I cannot shut my eyes to realities.” Consequently, Einstein became a proponent of collective security against fascism.
Fleeing from Nazi Germany, Einstein took refuge in the United States, which became his new home. Thanks to his renown, he was approached in 1939 by one of his former physics students, Leo Szilard, a Hungarian refugee who brought ominous news about advances in nuclear fission research in Nazi Germany. At Szilard’s urging, Einstein sent a warning letter to President Franklin Roosevelt about German nuclear progress. In response, the U.S. government launched the Manhattan Project, a secret program to build an atomic bomb.
Einstein, like Szilard, considered the Manhattan Project necessary solely to prevent Nazi Germany’s employment of nuclear weapons to conquer the world. Therefore, when Germany’s war effort neared collapse and the U.S. bomb project neared completion, Einstein helped facilitate a mission by Szilard to Roosevelt with the goal of preventing the use of atomic bombs by the United States. He also fired off an impassioned appeal to the prominent Danish physicist, Niels Bohr, urging scientists to take the lead in heading off a dangerous postwar nuclear arms race. Neither venture proved successful, and the U.S. government, under the direction of the new president, Harry Truman, launched the nuclear age with the atomic bombing of Japan. Einstein later remarked that his 1939 letter to Roosevelt had been the worst mistake of his life.
Convinced that humanity now faced the prospect of utter annihilation, Einstein resurrected one of his earlier ideas and organized a new campaign against war. “The only salvation for civilization and the human race,” he told an interviewer in September 1945, “lies in the creation of a world government, with security of nations founded upon law.” Again and again, he reiterated this message. In January 1946, he declared: “As long as there exist sovereign states, each with its own, independent armaments, the prevention of war becomes a virtual impossibility.” Consequently, humanity’s “desire for peace can be realized only by the creation of a world government.”
In 1946, he and other prominent scientists, fearful of the world’s future, established the Emergency Committee of Atomic Scientists. As chair of the new venture, Einstein repeatedly assailed militarism, nuclear weapons, and runaway nationalism. “We shall require a substantially new manner of thinking,” he said, “if mankind is to survive.”
Until his death in 1955, Einstein continued his quest for peace, criticizing the Cold War and the nuclear arms race and calling for strengthened global governance as the only “way out of the impasse.” Today, as we face a violent, nuclear-armed world, Einstein’s warnings about unrestrained nationalism and his proposals to control it are increasingly relevant.
Documenting the Debate Over the Use of Nuclear Weapons Against Japan
Einstein-Szilard Letter to President Franklin D. Roosevelt, August 2, 1939
Source: https://ahf.nuclearmuseum.org/ahf/key-documents/einstein-szilard-letter/
Background: Albert Einstein was the world’s most renowned physicist and a Nobel Prize winner. He fled Germany in the 1930s and established himself in the United States. Nuclear scientists Leo Szilard, Eugene Wigner, and Edward Teller, refugees from Nazi occupied Europe, persuaded Einstein to send a letter to President Franklin D. Roosevelt warning him of the possibility that Germany could develop an atomic bomb. In this letter, Einstein urged Roosevelt to support a program to develop atomic weapons.
“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 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 unofficial 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 Weizsäcker, is attached to the Kaiser-Wilhelm-Institut in Berlin where some of the American work on uranium is now being repeated.
The Franck Report, Report of the Committee on Political and Social Problems
Manhattan Project “Metallurgical Laboratory,” University of Chicago, June 11, 1945
Sources: https://ahf.nuclearmuseum.org/ahf/key-documents/franck-report/; https://thebulletin.org/2020/08/prominent-nuclear-scientists-did-not-recommend-the-atomic-bombings-of-japan/
Background: As the U.S. drew up plans to drop the first atomic bomb in August 1945, a group of scientists at the University of Chicago prepared a report arguing against the use of the bomb. Headed by James Franck and including notable scientists such as Leo Szilard and Glenn Seaborg, a Nobel laureate. The classified document was submitted to the Interim Committee, a group appointed by President Truman to advise him on the use of the bomb, in June 1945, one month before the Trinity test and two months before Hiroshima and Nagasaki. The Interim Committee rejected their recommendations.
A) “The development of nuclear power not only constitutes an important addition to the technological and military power of the United States, but also creates grave political and economic problems for the future of this country.”
B) “Nuclear bombs cannot possibly remain a ‘secret weapon’ at the exclusive disposal of this country, for more than a few years. The scientific facts on which their construction is based are well known to scientists of other countries. Unless an effective international control of nuclear explosives is instituted, a race of nuclear armaments is certain to ensue following the first revelation of our possession of nuclear weapons to the world. Within ten years other countries may have nuclear bombs, each of which, weighing less than a ton, could destroy an urban area of more than ten square miles. In the war to which such an armaments race is likely to lead, the United States, with its agglomeration of population and industry in comparatively few metropolitan districts, will be at a disadvantage compared to the nations whose population and industry are scattered over large areas.”
C) “We believe that these considerations make the use of nuclear bombs for an early, unannounced attack against Japan inadvisable. If the United States would be the first to release this new means of indiscriminate destruction upon mankind, she would sacrifice public support throughout the world, precipitate the race of armaments, and prejudice the possibility of reaching an international agreement on the future control of such weapons.”
D) “Much more favorable conditions for the eventual achievement of such an agreement could be created if nuclear bombs were first revealed to the world by a demonstration in an appropriately selected uninhabited area.”
Recommendation of the Scientific Panel of the Interim Committee
Sources: https://nsarchive2.gwu.edu/NSAEBB/NSAEBB162/19.pdf; https://teachingamericanhistory.org/document/recommendations-on-the-immediate-use-of-nuclear-weapons/
Background: The panel that issued this report to Secretary of War Henry Stimson consisted of four prominent physicists who were part of the Manhattan Project, J. Robert Oppenheimer, Director of the Los Alamos Laboratory; Enrico Fermi, lead scientist for the first nuclear reactor at the University of Chicago Met Lab; Arthur Compton, Nobel laureate and head of the Metallurgical Laboratory; and Ernest Lawrence, Nobel laureate and head of the Radiation Laboratory at UC Berkeley.
“You have asked us to comment on the initial use of the new weapon. This use, in our opinion, should be such as to promote a satisfactory adjustment of our international relations. At the same time, we recognize our obligation to our nation to use the weapons to help save American lives in the Japanese war.
(1) To accomplish these ends we recommend that before the weapons are used not only Britain, but also Russia, France, and China be advised that we have made considerable progress in our work on atomic weapons, and that we would welcome suggestions as to how we can cooperate in making this development contribute to improved international relations.
(2) The opinions of our scientific colleagues on the initial use of these weapons are not unanimous: they range from the proposal of a purely technical demonstration to that of the military application best designed to induce surrender. Those who advocate a purely technical demonstration would wish to outlaw the use of atomic weapons, and have feared that if we use the weapons now our position in future negotiations will be prejudiced. Others emphasize the opportunity of saving American lives by immediate military use, and believe that such use will improve the international prospects, in that they are more concerned with the prevention of war than with the elimination of this specific weapon. We find ourselves closer to these latter views; we can propose no technical demonstration likely to bring an end to the war; we see no acceptable alternative to direct military use.
(3) With regard to these general aspects of the use of atomic energy, it is clear that we, as scientific men, have no proprietary rights. It is true that we are among the few citizens who have had occasion to give thoughtful consideration to these problems during the past few years. We have, however, no claim to special competence in solving the political, social, and military problems which are presented by the advent of atomic power.”
Petition to the President of the United States, July 17, 1945
Source: https://ahf.nuclearmuseum.org/ahf/key-documents/szilard-petition/
Background: Nuclear physicist Leo Szilard, a refugee from Hungary who worked on the Manhattan Project, drafted a petition to President Harry Truman in the summer of 1945 hoping to avert the use of the atomic bomb against Japan. The petition was signed by seventy other scientists but was not seen by the President or the Secretary of War before the first atomic bomb was dropped on Hiroshima. Albert Einstein and Robert Oppenheimer were not listed as signers.
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 the 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 until 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 pursuit 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 the 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 consideration presented in this petition as well as all the other moral responsibilities which are involved.
A Policy for Survival: A Statement by the Emergency Committee of Atomic Scientists
Published in the June 1948 issue of the Bulletin of the Atomic Scientists
Background: The Emergency Committee of Atomic Scientists was formed in May, 1946, by Albert Einstein, R.F. Bacher, Hans A. Bethe, Edward U. Condon, R. Hogness, Leo Szilard, Harold C. Urey, and V.F. Weisskopf. Their objective was to encourage and further the peaceful uses of atomic energy and to do this they would solicit private contributions in support of the work of the National Committee for Atomic Information.
“Two years ago this month the United Nations Atomic Energy Commission was in process of formation. Now the discussions on international control of atomic energy are about to be adjourned indefinitely, perhaps never again to be resumed. One of the most fateful events in history has passed almost unnoticed. Its importance must be realized: its lesson for mankind must be made clear. To clarify the importance of the collapse of these discussions, we reiterate here our Six Point Statement published originally on November 17, 1946:
- Atomic bombs can now be made cheaply and in large number. They will become more destructive.
- There is no military defense against atomic bombs and none is to be expected.
- Other nations can rediscover our secret processes by themselves.
- Preparedness against atomic war is futile, and if attempted, will ruin the structure of our social order.
- If war breaks out, atomic bombs will be used and they will surely destroy our civilization.
- There is no solution to this problem except international control of atomic energy, and ultimately, the elimination of war.”












































