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Photo of members of the Chicago Pile-1 team at the University of Chicago, 1946

Manhattan Project Scientists Believed the Way We Get Out Alive is World Government

Scientists played an important role in influencing policy and drawing serious attention to arms control. Can they do the same today?

Words: John R. Emery and Anna Pluff
Pictures: National Security Research Center / Los Alamos National Laboratory

“I told them that we did not regard [the atomic bomb] as a new weapon merely but as a revolutionary change in the relations of man to the universe and that we wanted to take advantage of this; that the project might even mean the doom of civilization or it might mean the perfection of civilization; that it might be a Frankenstein which would eat us up or it might be a project ‘by which the peace of the world would be helped in becoming secure.’”

  • Secretary of War Henry Stimson’s Diary entry on May 31, 1945

Today, nuclear deterrence seems almost an inevitability of international relations. After the Trinity test in 1945 and the Soviet atomic test in 1949, unilateral disarmament seemed impossible as a Cold War arms-race dynamic ensued. However, the scientists of the Manhattan Project foresaw the certainty of such an arms race and envisioned more and more destructive atomic weaponry. 

Rather than advocating a theory of deterrence, those closest to the creation of the bomb articulated a radical alternative to living with the security dilemma of nuclear-armed states. Even before Trinity, a scientific movement had begun for world government control over nuclear energy. It was envisioned as a type of world federalism whereby the only possessor of nuclear weapons would be the world state entity. Today, such a concept seems far-fetched, yet it appeared as an absolute necessity in the aftermath of two world wars, the founding of the UN, and the creation of the most destructive weapon in history.

Rethinking nuclear deterrence requires conceptualizing alternative futures rather than the possibility of a failure of nuclear deterrence, accidental launch, or intentional use. Re-examining the scientists’ movement, despite its perceived failure, reveals the contingencies of deterrence and the possibility of a very different post-nuclear world. The early nuclear-era solutions offered by scientists and even policymakers might inform new directions today. To imagine that deterrence will never fail confines leaders and policymakers to outdated solutions in a rapidly changing world. With President Vladimir Putin weaponizing nuclear risk to wage a war of aggression against Ukraine, China expanding its minimum deterrence posture, and the United States prioritizing nuclear modernization, can we continue to rely on the Cold War deterrence model?

The national security state of the Cold War and Red Scare pushed aside reasonable scientific assessments and activism in the early nuclear era. Instead of the peaceful use of nuclear energy and disarmament, the Cold War beckoned an unprecedented arms race and a culture of secrecy rather than cooperation and exchange that the scientists advocated. Ultimately, the calls for world government to control nuclear weaponry seem further today than in 1945 and are clearly no longer a feasible solution. Nevertheless, if we are to rethink deterrence in the age of a multipolar world, we need to see the possible alternative paths not taken by those closest to the creation of the bomb. Our goal is to inspire a conversation versed in the rich historical record of the Manhattan Project to propose novel ideas for possible future worlds today that minimize the risks of nuclear use by welcoming the revival of scientific activism and thought into the policy-making process.

World Government

One World or None” represented the leading conviction of scientists, journalists, and politicians regarding the new world created by the atomic bomb. The top nuclear scientists — with about half of the essays written by Nobel Laureates — urgently promoted this message through a series of essays. Notable contributions include J. Robert Oppenheimer, Albert Einstein, Niels Bohr, and Leo Szilard. Nuclear one worldism represented a theory of state-building fit for the nuclear age, in which the security crisis would be solved by forming what political scientist Daniel Deudney termed an omnistate that would control the world’s nuclear energy.

Recognizing the immense political, moral, and catastrophic consequences of the nuclear bomb, scientists sought to influence the government and the public on the necessity of international cooperation on atomic issues. Many scientists saw scientific internationalism as foundational for creating an international authority for atomic energy control. Scientific internationalism was described by the Editor of the Bulletin of the Atomic Scientists, Eugene Rabinowitch, as a “set of ecumenical traditions” that scientists adhered to by recognizing the universal value of science and the need for unrestricted scientific exchange across nations. Scientific internationalism would be a foundation of world government by enhancing trust and collaboration across countries.

While not all the scientists who worked on the atomic bomb might have believed in international control, many of them seriously considered the political implications of their work, allowing scientists to exert influence on the highest echelons of policy briefly.

Because many scientists believed in the importance of international contact as the basis for peace and security, they often felt an ethical and political responsibility to promote global atomic control. For example, as expressed in the 1944 Jeffries Report — an outline of the implications of nuclear energy completed by Manhattan Project physicists like Enrico Fermi, Arthur Compton, and James Franck — scientists felt that they had a “moral responsibility” to “enlighten public opinion” and to “strive for the establishment of efficient international supervision over all aspects of [nuclear energy].”

Letters on World Government

Scientists at Oak Ridge, Tennessee, took a particular interest in the development of a world federal government as a solution to the inevitability of nuclear proliferation and its potential to hold the world hostage. Based on extensive archival data at the University of Chicago Library in the Hanna Holborn Gray Special Collections Research Center, we present the origins of this radical idea. A group of four Oak Ridge scientists — John L. Balderston, Jr., Dieter M. Gruen, W.J. McLean, and David B. Wehmeyer — undertook the “Letters on World Government” project as representatives of the Atomic Oak Ridge Scientists (AORS) and the Oak Ridge Engineers and Scientists (ORES). The group wrote to 154 primarily American and British leaders in science, culture, and politics, soliciting their opinions and advice about establishing a world government. Over the next year, as they received more than 100 responses to the letter, the committee compiled a final report in 1947.

On November 13, 1945, the editorial committee of the Atomic Scientists at Clinton Laboratories, Oak Ridge, Tennessee, issued the following statement

“Atomic power can make life immensely better, but it can also destroy it entirely…We have been convinced that the atomic bomb must be controlled…We cannot tolerate another war…Not only will nations have these bombs, but there is no defense against them…There has to be international control with teeth in it and placed above the sovereignty of nations…Only with world wide [sic] control can we look forward to a lasting era of peace.”

In their solicitation letter, Balderston et al. recognized that with nuclear weapons, “another war could mean the destruction of present civilization, [and] we are trying to learn how war can be prevented.” Their solution moved beyond the UN Organization (known as UNO at the time) toward a world government to prevent atomic destruction. They concluded that “lasting peace cannot be achieved by any system of confederation but only by a world government” and thus “all nations must turn over to it all of their external sovereignty, including power to declare war and keep armies…” 

They recognized the inherent difficulties, including the unwillingness of states to give up sovereignty. Nevertheless, they solicited opinions on whether world government should be established immediately (as early as November 1945) or continue with the UNO confederation with an eventual gradual move toward world government. Ultimately, they viewed it necessary for “this world government to be set up soon if another war is to be averted.” However, disagreements/concerns/dissension between scientists emerged because of differing opinions on the political structure of international authority. The AORS and the ORES became frustrated with the emerging UNO structure and believed that the veto power of the UN Charter “must be replaced by a system of world law from which no state is exempt.”
One of their proposed resolutions to be voted on by members at ORES clearly stated their position:

ORES Statement
ORES Statement – Donald MacRae Collection, [Box 2, Folder 1], “The Atomic Engineer & Scientist” Hanna Holborn Gray Special Collections Research Center, University of Chicago Library, pg. 5.

Survey on World Government

Volume II issue 9 of The Atomic Engineer and Scientist bulletin on March 16, 1946, shared the results of a World Government Poll of both wider Oak Ridge employees and specifically ORES members in attendance of their regular meetings. Twelve hundred were surveyed and asked the following questions: 

If a world government can be established that will:

  1. Guarantee the same rights to every person in the world.
  2. Have among its powers the sole right to maintain any army and control atomic energy.
  3. Enforce its laws on all peoples and governments by means of a world police force.
  1. Would you favor such a world government? 
  2. Do you think that the United States should work towards the formation of a world government immediately?
  3. Do you believe that the UNO, as it now stands, is going to prevent war?
  4. Do you believe that a world government, as defined above, would prevent war?

The following summarizes the answers to these questions:

World Government Poll
World Government Poll – Donald MacRae Collection, [Box 2, Folder 1], “The Atomic Engineer & Scientist” Hanna Holborn Gray Special Collections Research Center, University of Chicago Library, pg. 5.

It is clear that there was an overwhelming surge of confidence in the need for world government and its importance in stemming both a nuclear crisis and another world war. Scientists began to voice their opinions publicly. 

In Their Own Words: World Government in the Atomic Age

Scientists often exhibited a formidable ability to navigate scientific and political issues in addressing the security implications of nuclear power. While not all the scientists who worked on the atomic bomb might have believed in international control, many of them seriously considered the political implications of their work, allowing scientists to exert influence on the highest echelons of policy briefly. Ultimately, through these excerpts of the letters on world government, we can gain private insights into leading scientific views of global control of nuclear energy and nuclear one worldism.

Enrico Fermi, known as the “Pope of Physics,” agreed with the scientific consensus at the time that “some form of international control of the new weapons is a very desirable goal to work for…” but there would be “great difficulties for achieving this purpose.” However, Fermi strongly felt that “it would be very dangerous to participate in a weak international agreement. I believe that this country would be better off with no agreement than with one that could be violated easily by some of its participants.”

Scanned at the American Institute of Physics, Emilio Segre Visual Archives.
Enrico Fermi — University of Chicago, Courtesy AIP Emilio Segré Visual Archives.

Chemist of the Manhattan Project Harold Urey noted three things the scientists had been doing well and needed to be continued. First, the atomic scientists have “impressed people with the magnitude and danger of the bomb.” Second, “we have emphasized that there is no defense against it.” And third, “we have discussed the technical feasibility of inspection.” He highlighted that there was a problem with scientists discussing the “political implementation of our ideas.” He proposed getting “lectures from people who have been studying the problem of international organization for years” to present to the physical scientists. Ultimately, Urey recognized that “the sovereignty of a world government must reside in the people and that world government must make laws for its citizens, not for the states.”

Scientists were not the only ones seeking a suitable answer to the impending nuclear question. Historian and political theorist Campbell Craig explored the widespread faith and belief in world government in his article “Solving the Nuclear Dilemma: Is a World State Necessary?” Before deterrence was codified, many thinkers and politicians believed the nuclear dilemma could only be solved by building an authoritative world state. President Harry S. Truman initially commissioned a Department of State report to create a potential blueprint for achieving world government. The Acheson-Lilienthal Report was released in January 1946 and proposed a detailed plan for a UN-like body that would regulate atomic energy and complete verification processes and inspections. 

Achieving the approval of the USSR for such a plan was another issue. According to Craig, many recognized that the Soviet Union would be unwilling to accept a proposal in which the United States would keep its arsenal while simultaneously trusting that a Western agency implement a regime of verification before eventually taking control of the American atomic arsenal. Moreover, the possibility of Soviet espionage or deceit convinced Truman that the Acheson-Lilienthal plan was far too challenging to implement. 

Instead, Truman authorized Bernard Baruch to develop a new plan. Baruch submitted a modified plan to the UN in 1946 that deemphasized the concept of an international authority and largely ignored the idea of using scientific exchange to create the basis for trust and negotiations between the USSR and the United States. This move disappointed physicists arguing for “One World or None,” and Baruch left little room for negotiation. When a reporter asked Baruch what he thought of the Acheson-Lilienthal report, he deliberately turned off his hearing aid. Many scientists were unnerved by Baruch’s unwillingness to cooperate and consult with scientists. Historian Joseph Manzione notes, “Many scientists came to agree with Oppenheimer that the day Truman appointed Baruch, any chance for cooperation with the Soviet Union or the international order they had hoped for vanished.”

Einstein and Szilard Lobby for World Government

In his interview with New York Times Magazine on June 23, 1946, Einstein responded to queries about atomic weaponry, noting that “a new type of thinking is essential if mankind is to survive and move to higher levels.”

Einstein's "Only Then Shall We Find Courage" – Copyright 2014, Special Collections & Archives Research Center Oregon State University Libraries and Press.
Einstein's "Only Then Shall We Find Courage" – Copyright 2014, Special Collections & Archives Research Center Oregon State University Libraries and Press.

He unequivocally states that in light of the power of the atomic age, “a world authority and an eventual world state is not just desirable in the name of brotherhood, they are necessary for survival.” The atomic age required a radical redefinition of the state’s relation to war and violence in international affairs: “Today we must abandon competition and secure cooperation. This must be the central fact in all our considerations of international affairs; otherwise we face certain disaster. Past thinking and methods did not prevent world wars. Future thinking must prevent wars.” Thus, Einstein, along with the Oak Ridge scientists and engineers, recognized the immense shift that atomic weapons had created in the international system. 

Einstein went on to argue that the emerging concept of nuclear deterrence was inadequate: “America has a temporary superiority in armament, but it is certain that we have no lasting secret…our temporary superiority gives this nation the tremendous responsibility of leading mankind’s effort to surmount the crisis.” Ultimately because there was no adequate defense against atomic weapons; our “defense is not in armaments, nor in science, nor in going underground. Our defense is in law and order.” 

In 1946, Einstein founded the “Emergency Committee of Atomic Scientists” to educate the American public about the dangers of nuclear war. As a member of the board of Trustees, Leo Szilard outlined what he saw as the central analysis of the situation over control of atomic energy in 1947. He cautioned that in the next 10-15 years, the gloomy picture many physicists paint is woefully inadequate. They speak about “Nagasaki bombs,” but he was concerned with “giant bombs which disperse radioactive substances in the air…far away from our cities.”

Szilard recognized that traditional foreign policy was designed “to lengthen the interval between two wars,” which is wholly inadequate for the age of nuclear weapons. Thus, “no balance of power in the original meaning of the term,” between Russia and the United States, “is possible in such a situation” where the two governments are positioning themselves to win a war against each other in the atomic era. Szilard understood the security dilemma that Russia might fear a preventive war by the United States and wrote, “As long as [we] have bombs and Russia has none, she cannot be certain we will not attack her. At present, we propose to eliminate atomic bombs from all national armaments by setting up an international control agency, and we offer to the Russians, as the main inducement, to discard our own bombs at an early date and thus to free Russia from the danger of being attacked.” 

1-Einstein and Szilard letter to Roosevelt NNSA
Albert Einstein and Leo Szilard. Courtesy of Atomic Heritage Foundation.

Ultimately, Szilard theorized that the security dilemma would drive Russia to acquire an atomic bomb and lead to an ever-increasing armaments race, causing war rather than lasting peace. The Emergency Committee and Szilard viewed this as unacceptable and considered the proposal of international control and US disarmament the only viable option before a Soviet atomic test.

According to political theorist Luis Cabrera, while Einstein’s colleagues at the Emergency Committee of Atomic Scientists lobbied for world government control of nuclear weapons, he staged a publicity tour for full global government. Yet with the fate of the Acheson-Lilienthal and Baruch plan faltering in the face of US-Soviet tensions, momentum for world government waned. 

Atomic Power and World Order

An alternative path of nuclear deterrence also emerged in 1946. The essay series, edited by Bernard Brodie, entitled “The Absolute Weapon: Atomic Power and World Order,” also made its rounds, influencing thinking about living with the bomb in the current sovereign state system instead of UN expansion into world federal government. 

Brodie is most well-known for his standalone contributions to this volume, including the famous quote: “Thus far the chief purpose of our military establishment has been to win wars. From now on its chief purpose must be to avert them. It can have almost no other useful purpose.” However, the last contribution of this collection by William T.R. Fox — associate director of the Yale Institute of International Studies — laid out the arguments against world government in an essay: “The International Control of Atomic Weapons.” In a scathing critique of the scientific movement and Einstein’s campaign of public education, Fox viewed it as naïve and impossible to get the Soviet Union or even the American public to agree. Thus, he concluded that “the vexing and grave problem of international control of atomic weapons is not now within our grasp.” Competing against the scientists’ movement was a group of thinkers in international relations in this volume that put forth the deterrence norm of atomic weaponry. As Frederick S. Dunn noted in the introduction to “The Absolute Weapon” volume, “the atomic bomb is one of the most persuasive deterrents to adventures in atomic warfare that could be devised. It is particularly well adaped [sic] to the technique of retaliation.” 

In his chapter “The Absolute Weapon,” Peter E. Corbett directly addressed the subject of world government. He stated, “One instantaneous effect of the bomb that fell on Hiroshima on August 6, 1945, was a revival of the federalist movement.” Corbett believed those that once viewed world government as “too remote to be worth striving for, were converted overnight to the view that the race could not survive unless states gave up their sovereignty and merged into one universal union.” He instead advocated for a system of atomic proliferation control within the current United Nations Organization system while recognizing the “natural tendency” of sovereign states fearing a great power to align in “bilateral treaties of alliance, or in regional pacts, or both.” Thus, Corbett argued against world government as it is not in the nature of sovereign states, and that the UNO, along with constant effort to devise a “system of control over the use of atomic energy” were best suited to prevent catastrophe. 

Ultimately, we can view the scientists’ movement for world government in direct contrast to the advocacy of deterrence and a changing world order that the authors of “The Absolute Weapon” present. However, the centrality of addressing and critiquing the movement for world government is indeed a testament to the power of scientific one-worldism at the time.

Scientists Against Deterrence

In a scathing critique of what would become the mentality of Cold War deterrence, Einstein stated: “I do not believe that we can prepare for war and at the same time prepare for a world community. When humanity holds in its hand the weapon with which it can commit suicide, believe that to put more power into the gun is to increase the probability of disaster.” Thus, not only would it increase the probability of disaster, but it would also create massive expenditures for the United States.

He added, “Meanwhile, men high in government propose defense or war measures which would not only compel us to live in a universal atmosphere of fear but would cost untold billions of dollars and ultimately destroy our American free way of life — even before a war.” Ultimately, the conclusion then must be in line with what “[m]any leaders express well the need for world authority and an eventual world government, but actual planning and action to this end have been appallingly slow.”

The Cold War’s security culture ultimately curtailed the scientists’ movement for world government. Nonetheless, the ability of scientists to climb and influence the highest rungs of policy reveals a vital place for scientific insight into policymaking today. The scientists’ foresight into a post-nuclear world may have prevented the Cold War arms build-up and the rising tensions that nearly led to nuclear exchanges. Rather than deterrence, scientific internationalism might have opened up new pathways for safety and security in the 20th century and beyond. 

The release of a statement by the scientists of an atomic bomb project at Clinton Laboratories spelled out their position. In a prescient prediction of the coming Cold War nuclear arms race, they outlined the inevitable consequences of a course of “narrow nationalism and irrational secrecy.” An atomic armaments race proceeding with ever greater acceleration, a deepening of mutual suspicion, distrust, and fear; the growth of the psychological necessity for striking first in order to feel any assurance of safety; and ultimately, war on a scale so horrible as to defy description. It is clear that the outcome of this policy will not be national security but world wide [sic] chaos.” As they saw it, the only solution for collective security was that a “World Security Council must be made the only custodian of nuclear power in the world.” Ultimately, “any feeling of choice in the matter is purely illusory…We must recognize at last that it is only through mutual understanding and trust that mankind can hope to banish forever the fear of war.”

Robert Serber, Director of Physical Measurements with the Atomic Bomb mission in Japan, returned to Los Alamos on November 13, 1945, and presented his findings. After describing the horror he witnessed in Hiroshima and Nagasaki of corpses, burned bodies, and the living sick with radiation poisoning, he was encouraged by the above Clinton Laboratories “statement of a group of scientists working on the project in the United States urging the internationalization of the atomic bomb.” He hoped there would be “a unanimous insistence for the free interchange among all nations of information dealing with atomic power. The alternative seems to me a desperate arms race and one that can only end in terrible catastrophe.”


Today, over 12,500 nuclear weapons exist in the world. As historian Audra J. Wolfe remarks, organizations of scientists like the Federation of Atomic Scientists (later the Federation of American Scientists) actively worked to promote world government. In 1946, FAS’s Committee for Foreign Correspondence solicited the views of 3,000 scientists, including those in the Soviet Union, on preventing nuclear war. For a brief moment, it appeared that the advice of the scientists might compel the United States to participate in a world government. However, as noted, the 1946 Baruch plan heavily limited international exchange and the premise for global control. Without a multinational authority to limit proliferation, the nuclear arms race defined the rest of the Cold War, and defense intellectuals codified deterrence as the leading solution to the nuclear crisis. 

Moreover, the Cold War’s security culture ultimately curtailed the scientists’ movement for world government. As politicians began to view any form of international exchange and collaboration, especially with the Soviets, as a dire security threat, world government momentum waned and was viewed with deep suspicion. Nonetheless, the ability of scientists to climb and influence the highest rungs of policy reveals a vital place for scientific insight into policymaking today. The scientists’ foresight into a post-nuclear world may have prevented the Cold War arms build-up and the rising tensions that nearly led to nuclear exchanges. Rather than deterrence, scientific internationalism might have opened up new pathways for safety and security in the 20th century and beyond. 

Yet, today, we still hold on to deterrence. Can nuclear deterrence hold indefinitely?

As scholar Campbell Craig writes: “In the long term, deterrence is bound to fail: to predict that it will succeed forever, never once collapsing into a nuclear war, is to engage in a utopian and ahistorical kind of thinking. … When it fails, the ensuing war is likely to kill hundreds of millions of people, and possibly exterminate the human race.” 

Examining the history of the scientists’ movement reveals the stunning role scientists played in influencing policy and their ability to draw serious attention to world government. History does not simply show us dead ends but imagined futures. The risk of nuclear catastrophe is heightened — with the withdrawal from arms control treaties, increasing threats between the nexus of technology, AI, and nuclear, and the massive modernization of nuclear arsenals. There is still a place for scientists to bridge the gap between research and consequence, lend their expertise to policy, and help shape a safer world.

John R. Emery and Anna Pluff

John R. Emery is an assistant professor of international security in the Department of International and Area Studies at the University of Oklahoma. His research focuses on issues of technology in international relations, AI ethics, security studies, wargaming, ethics of war, and nuclear history. He can be found on LinkedIn here. Anna Pluff is a New Voices in Nuclear Weapons Fellow at the Federation of American Scientists. She can be found on LinkedIn here.

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