Early efforts In 1945, Britain and Canada made an early call for international discussions on the control of atomic power, anticipating the global implications of nuclear technology. At the time, the U.S. had not yet developed a cohesive policy or strategy regarding nuclear weapons.
Vannevar Bush, who had been instrumental in initiating and overseeing the
Manhattan Project, sought to leverage this moment to advance his long-term goal of banning nuclear weapons production, despite the project's role in developing them. As a first step in this direction, Bush proposed an international agency dedicated to nuclear control. Bush unsuccessfully argued in 1952 that the US pursue a test ban agreement with the Soviet Union before testing its first thermonuclear weapon, but his interest in international controls was echoed in the 1946
Acheson–Lilienthal Report, which had been commissioned by President
Harry S. Truman to help construct US nuclear weapons policy.
J. Robert Oppenheimer, who had led
Los Alamos National Laboratory during the Manhattan Project, exerted significant influence over the report, particularly in its recommendation of an international body that would control production of and research on the world's supply of
uranium and
thorium. A version of the Acheson-Lilienthal plan was presented to the
United Nations Atomic Energy Commission (UNAEC) as the
Baruch Plan in June 1946. The Baruch Plan proposed that an International Atomic Development Authority would control all research on and material and equipment involved in the production of atomic energy. Though
Dwight D. Eisenhower, then the
Chief of Staff of the United States Army, was not a significant figure in the Truman administration on nuclear questions, he did support Truman's nuclear control policy, including the Baruch Plan's provision for an international control agency, provided that the control system was accompanied by "a system of free and complete inspection." test of 1952, an early thermonuclear detonation The Soviet Union dismissed the Baruch Plan as a US attempt to secure its nuclear dominance, and called for the US to halt weapons production and release technical information on its program. The Acheson–Lilienthal paper and Baruch Plan would serve as the basis for US policy into the 1950s. Between 1947 and 1954, the US and Soviet Union discussed their demands within the United Nations Commission for Conventional Disarmament. A series of events in 1954, including the Castle Bravo test and spread of fallout from a Soviet test over Japan, redirected the international discussion on nuclear policy. Additionally, by 1954, both US and Soviet Union had assembled large nuclear stockpiles, reducing hopes of complete disarmament. In the early years of the
Cold War, the US approach to nuclear control reflected a strain between an interest in controlling nuclear weapons and a belief that dominance in the nuclear arena, particularly given the size of Soviet conventional forces, was critical to US security. Interest in nuclear control and efforts to stall proliferation of weapons to other states grew as the Soviet Union's nuclear capabilities increased.
After Castle Bravo: 1954–1958 In 1954, just weeks after the
Castle Bravo test, Indian Prime Minister
Jawaharlal Nehru made the first public call for a "standstill agreement" on nuclear testing. Nehru viewed a testing moratorium as a crucial first step toward broader and more comprehensive arms control agreements, reflecting his commitment to nuclear disarmament and global peace. Its research findings confirmed a significant build-up of strontium-90 in bones of babies and helped galvanise public support for a ban on atmospheric nuclear testing in the US. both sought to tamp down on these fears, arguing that fallout [at the dose levels of US exposure] were fairly harmless and that a test ban would enable the Soviet Union to surpass the US in nuclear capabilities. Teller also suggested that testing was necessary to develop nuclear weapons that produced less fallout. Support in the US public for a test ban to continue to grow from 20% in 1954 to 63% by 1957. Moreover, widespread antinuclear protests were organized and led by theologian and
Nobel Peace Prize laureate
Albert Schweitzer, whose appeals were endorsed by
Pope Pius XII, and
Linus Pauling, the latter of whom organized an anti-test petition signed by more than 9,000 scientists across 43 countries (including the infirm and elderly
Albert Einstein). The AEC would eventually concede, as well, that even low levels of radiation were harmful. It was a combination of rising public support for a test ban and the shock of the 1957 Soviet
Sputnik launch that encouraged Eisenhower to take steps towards a test ban in 1958. that the Soviet Union could conduct secret nuclear tests. In 1958, at the request of Igor Kurchatov, Soviet nuclear physicist and weapons designer
Andrei Sakharov published a pair of widely circulated academic papers challenging the claim of Teller and others that a clean, fallout-free nuclear bomb could be developed, due to the formation of
carbon-14 when nuclear devices are detonated in the air. A one-megaton clean bomb, Sakharov estimated, would cause 6,600 deaths over 8,000 years, figures derived largely from estimates on the quantity of
carbon-14 generated from atmospheric nitrogen and the contemporary risk models at the time, along with the assumption that the world population is "thirty billion persons" in a few thousand years. In 1961, Sakharov was part of the design team for a 50 megaton "clean bomb", which has become known as the
Tsar Bomba, detonated over the island of
Novaya Zemlya. The Soviet declaration concerned the British government, which feared that the moratorium might lead to a test ban before its own testing program was completed. Following the Soviet declaration, Eisenhower called for an international meeting of experts to determine proper control and verification measures—an idea first proposed by British
Foreign Secretary Selwyn Lloyd. The moratorium would last for close to three years. The Conference on the Discontinuance of Nuclear Tests convened in Geneva at Moscow's request (the Western participants had proposed
New York City). The US delegation was led by
James Jeremiah Wadsworth, an envoy to the UN, the British by
David Ormsby-Gore, the
Minister of State for Foreign Affairs, and the Soviets by
Semyon K. Tsarapkin, a disarmament expert with experience dating back to the 1946 Baruch Plan. The Geneva Conference began with a Soviet draft treaty grounded in the Geneva System. The three nuclear weapons states (the "original parties") would abide by a test ban, verified by the Geneva System, and work to prevent testing by potential nuclear states (such as France). This was rejected by Anglo-American negotiators due to fears that the verification provisions were too vague and the Geneva System too weak. Shortly after the Geneva Conference began in the fall of 1958, Eisenhower faced renewed domestic opposition to a comprehensive test ban as Senator
Albert Gore Sr. argued in a widely circulated letter that a partial ban would be preferable due to Soviet opposition to strong verification measures. The Gore letter did spur some progress in negotiations, as the Soviet Union allowed in late November 1958 for explicit control measures to be included in the text of the drafted treaty. By March 1959, the negotiators had agreed upon seven treaty articles, but they primarily concerned uncontroversial issues and a number of disputes over verification persisted. First, the Soviet verification proposal was deemed by the West to be too reliant on self-inspection, with control posts primarily staffed by citizens of the country housing the posts and a minimal role for officials from the international supervisory body. The West insisted that half of a control post staff be drawn from another nuclear state and half from neutral parties. Second, the Soviet Union required that the international supervisory body, the Control Commission, require unanimity before acting; the West rejected the idea of giving Moscow a veto over the commission's proceedings. Finally, the Soviet Union preferred temporary inspection teams drawn from citizens of the country under inspection, while the West insisted on permanent teams composed of inspectors from the Control Commission. Additionally, despite the initial positive response to the Geneva experts' report, data gathered from Hardtack operations of 1958 (namely the underground
Rainier shot) would further complicate verification provisions as US scientists, including Hans Bethe (who backed a ban), became convinced that the Geneva findings were too optimistic regarding detection of underground tests, though Macmillan warned that using the data to block progress on a test ban might be perceived in the public as a political ploy. In early 1959, Wadsworth told Tsarapkin of new US skepticism towards the Geneva System. While the Geneva experts believed the system could detect underground tests down to five kilotons, the US now believed that it could only detect tests down to 20 kilotons (in comparison, the
Little Boy bomb dropped on
Hiroshima had an official yield of 13 kilotons). As a result, the Geneva detection regime and the number of control posts would have to be significantly expanded, including new posts within the Soviet Union. The Soviets dismissed the US argument as a ruse, suggesting that the Hardtack data had been falsified. In early 1959, a roadblock to an agreement was removed as Macmillan and Eisenhower, over opposition from the Department of Defense, agreed to consider a test ban separately from broader disarmament endeavors. The primary product of negotiations under Eisenhower was the testing moratorium without any enforcement mechanism. Ultimately, the goal of a comprehensive test ban would be abandoned in favor of a partial ban due to questions over seismic detection of underground tests. Political scientist
Robert Gilpin later argued that Eisenhower faced three camps in the push for a test ban. The first was the "control" camp, led by figures like Linus Pauling and astronomer
Harlow Shapley, which believed that both testing and possession of nuclear weapons was dangerous. Second, there was the "finite containment" camp, populated by scientists like Hans Bethe, which was concerned by perceived Soviet aggression but still believed that a test ban would be workable with adequate verification measures. Third, the "infinite containment" camp, of which Strauss, Teller, and members of the defense establishment were members, believed that any test ban would grant the Soviet Union the ability to conduct secret tests and move ahead in the arms race. The degree of Eisenhower's interest in a test ban is a matter of some historical dispute.
Stephen E. Ambrose writes that by early 1960, a test ban had become "the major goal of his Presidency, indeed of his entire career," and would be "his final and most lasting gift to his country." Conversely,
John Lewis Gaddis characterizes negotiations of the 1950s as "an embarrassing series of American reversals," suggesting a lack of real US commitment to arms control efforts. The historian Robert Divine also attributed the failure to achieve a deal to Eisenhower's "lack of leadership," evidenced by his inability to overcome paralyzing differences among US diplomats, military leaders, national security experts, and scientists on the subject.
Paul Nitze would similarly suggest that Eisenhower never formulated a cohesive test ban policy, noting his ability to "believe in two mutually contradictory and inconsistent propositions at the same time."
Renewed efforts and
Khrushchev in Vienna Upon assuming the presidency in January 1961,
John F. Kennedy was committed to advancing a comprehensive test ban on nuclear weapons. He quickly ordered a review of the U.S. negotiating position to revitalize stalled talks, as he believed
Eisenhower's previous approach had been "insufficient" in achieving meaningful progress toward nuclear disarmament. Kennedy saw the test ban as a critical step toward reducing nuclear proliferation and easing Cold War tensions. In making his case for a test ban, Kennedy drew a direct link between continued testing and nuclear proliferation, calling it the "'Nth-country' problem." While a candidate, Kennedy had argued, "For once
China, or France, or
Sweden, or half a dozen other nations successfully test an atomic bomb, the security of both Russians and Americans is dangerously weakened." He had also claimed that renewed testing would be "damaging to the American image" and might threaten the "existence of human life." On the campaign trail, Kennedy's test-ban proposal consisted of a continued US testing moratorium, expanded efforts to reach a comprehensive agreement, limit any future tests to those minimizing fallout, and expand research on fallout. Notably, early in his presidency, Kennedy also oversaw a significant increase in U.S. defense spending, a move that was soon mirrored by the
Soviet Union. This escalation intensified the arms race and placed the test-ban negotiations within a broader context of heightened military competition. Despite these growing tensions, Kennedy remained committed to pursuing a comprehensive test ban, recognizing it as a crucial step toward curbing the nuclear arms race. On 21 March 1961, test-ban negotiations resumed in Geneva and
Arthur Dean, a lead US envoy, offered a new proposal in an attempt to bridge the gap between the two sides. The early Kennedy proposal largely grew out of later Eisenhower efforts, with a ban on all tests but low-yield underground ones (below magnitude 4.75), which would be subject to a three-year moratorium. The US and UK proposed 20 on-site inspections per annum, while the Soviet Union proposed three. The verification procedures included in the Anglo-American plan were unacceptable to Tsarapkin, who responded with separate proposals rejected by the Western powers. After years of dormant or lethargic negotiations, American and British negotiators subsequently forged a strong working relationship and with Soviet negotiators found common ground on test restrictions later in 1962. After years of pursuing a comprehensive ban, Khrushchev was convinced to accept a partial ban, partly due to the efforts of Soviet nuclear scientists, including Kurchatov, Sakharov, and
Yulii Khariton, who argued that atmospheric testing had severe consequences for human health. Khrushchev had been concerned by a partial ban due to the greater US experience in underground tests; by 1962, the US had conducted 89 such tests and the Soviet Union just two (the Soviet focus had been on cheaper, larger-yield atmospheric tests). For this reason, many in the Soviet weapons industry argued that a partial ban would give the US the advantage in nuclear capabilities. Khrushchev would later recount that he saw test-ban negotiations as a prime venue for ameliorating tensions after the crisis in Cuba. Shocked by how close the world had come to
thermonuclear war,
Khrushchev proposed easing tensions with the U.S. In a letter to President Kennedy dated 30 October 1962, Khrushchev outlined a series of bold initiatives to prevent the possibility of nuclear war. His proposals included a non-aggression treaty between
NATO and the
Warsaw Pact, or even the disbanding of these military blocs; a treaty to cease all nuclear weapons testing; and the complete elimination of all nuclear weapons. He also suggested resolving the contentious issue of Germany by having both East and West formally recognize the existence of
West Germany and
East Germany, as well as calling for U.S. recognition of the government of mainland China. The letter invited counter-proposals and encouraged further exploration of these and other issues through peaceful negotiations. Additionally, Khrushchev invited
Norman Cousins, the editor of a major U.S. periodical and an anti-nuclear weapons activist, to serve as a liaison with President Kennedy. Cousins met with Khrushchev for four hours in December 1962. Cousins' secret mission was aided by
Pope John XXIII, who served as an intermediary; officially, Cousins was traveling to Rome on a personal basis, but from the Vatican he continued to the Soviet Union. Through Cousins' shuttle diplomacy in 1962 and 1963, the pontiff remained at the center of negotiations and helped ease misunderstandings between the two world leaders. Kennedy's response to Khrushchev's proposals was lukewarm but Kennedy expressed to Cousins that he felt constrained in exploring these issues due to pressure from hardliners in the US national security apparatus. However Kennedy pursued negotiations for a partial nuclear test ban. On 13 November 1962, Tsarapkin indicated that the Soviet Union would accept a proposal drafted by US and Soviet experts involving automated test detection stations ("black boxes") and a limited number of on-site inspections. The two sides disagreed over the number of black boxes, however, as the US sought 12–20 such stations and the Soviet Union rejected any more than three. On 28 December 1962, Kennedy lowered the US demand to 8–10 stations. On 19 February 1963, the number was lowered further to seven, as Khrushchev continued to insist on no more than three. Kennedy proceeded to announce an agreement with Khrushchev and Macmillan to promptly resume comprehensive test-ban negotiations in Moscow and a US decision to unilaterally halt atmospheric tests. As the nuclear powers pursued a test ban agreement, they also sought to contend with a rising communist China, which at the time was pursuing its own
nuclear program. In 1955,
Mao Zedong expressed to the Soviet Union his belief that China could withstand a first nuclear strike and more than 100 million casualties. In the 1950s, the Soviet Union assisted the Chinese nuclear program, but stopped short of providing China with an actual nuclear bomb, which was followed by
increasingly tense relations in the late 1950s and early 1960s. Khrushchev began the test-ban talks of 1958 with minimal prior discussion with China, and the two countries' agreement on military-technology cooperation was terminated in June 1959. Prior to the Moscow negotiations of the summer of 1963, Kennedy granted Harriman significant latitude in reaching a "Soviet-American understanding" vis-à-vis China. Secret Sino-Soviet talks in July 1963 revealed further discord between the two communist powers, as the Soviet Union released a statement that it did not "share the views of the Chinese leadership about creating 'a thousand times higher civilization' on the corpses of hundreds of millions of people." The Soviet Union also issued an ideological critique of China's nuclear policy, declaring that China's apparent openness to nuclear war was "in crying contradiction to the idea of
Marxism–Leninism," as a nuclear war would "not distinguish between imperialists and working people." The negotiations were inaugurated on 15 July 1963 at the
Kremlin with Khrushchev in attendance. Khrushchev reiterated that the Anglo-American inspection plan would amount to espionage, effectively dismissing the possibility of a comprehensive ban. Following the script of his 3 July 1963 speech, Khrushchev did not demand a simultaneous moratorium on underground testing and instead proposed a non-aggression pact. Under instruction from Washington, Harriman replied that the US would explore the possibility of a non-aggression pact in good faith, but indicated that while a test ban could be quickly completed, a non-aggression pact would require lengthy discussions. Additionally, such a pact would complicate the issue of Western access to
West Berlin. Harriman also took the opportunity to propose a non-proliferation agreement with would bar the transfer of nuclear weapons between countries. Khrushchev said that such an agreement should be considered in the future, but in the interim, a test ban would have the same effect on limiting proliferation. Following initial discussions, Gromyko and Harriman began examining drafts of a test-ban agreement. First, language in the drafted preamble appeared to Harriman to prohibit the use of nuclear weapons in self-defense, which Harriman insisted be clarified. Harriman additionally demanded that an explicit clause concerning withdrawal from the agreement be added to the treaty; Khrushchev believed that each state had a sovereign right to withdraw, which should simply be assumed. Harriman informed Gromyko that without a clause governing withdrawal, which he believed the US Senate would demand, the US could not assent. Ultimately, the two sides settled upon compromise language: Each Party shall in exercising its national sovereignty have the right to withdraw from the Treaty if it decides that extraordinary events, related to the subject matter of this Treaty, have jeopardized the supreme interests of its country. Gromyko and Harriman debated how states not universally recognized (e.g.,
East Germany and China) could join the agreement. The US proposed asserting that accession to the treaty would not indicate international recognition. This was rejected by the Soviet Union. Eventually, with Kennedy's approval, US envoys Fisher and McNaughton devised a system whereby multiple government would serve as
depositaries for the treaty, allowing individual states to sign only the agreement held by the government of their choice in association with other like-minded states. This solution, which overcame one of the more challenging roadblocks in the negotiations, also served to allay mounting concerns from Macmillan, which were relayed to Washington, that an agreement would once again be derailed. Finally, in an original Soviet draft, the signature of France would have been required for the treaty to come into effect. At Harriman's insistence, this requirement was removed. announces the agreement on 26 July 1963 The agreement was initialed on 25 July 1963, just 10 days after negotiations commenced. The following day, Kennedy delivered a 26-minute televised address on the agreement, declaring that since the invention of nuclear weapons, "all mankind has been struggling to escape from the darkening prospect of mass destruction on earth ... Yesterday a shaft of light cut into the darkness." Kennedy expressed hope that the test ban would be the first step towards broader rapprochement, limit nuclear fallout, restrict nuclear proliferation, and slow the arms race in such a way that fortifies US security. Kennedy concluded his address in reference to a Chinese
proverb that he had used with Khrushchev in Vienna two years prior. "'A journey of a thousand miles must begin with a single step,'" Kennedy said. "And if that journey is a thousand miles, or even more, let history record that we, in this land, at this time, took the first step." In a speech in Moscow following the agreement, Khrushchev declared that the treaty would not end the arms race and by itself could not "avert the danger of war," and reiterated his proposal of a NATO-Warsaw Pact non-aggression accord. Before the treaty was signed, Premier
Zhou Enlai requested a report from the
Second Ministry of Machine Building and relevant experts to address the implications. The experts asserted that the three countries participating in the ban had already conducted enough atmospheric tests such that the ban would have little impact on their nuclear programs. On 5 August 1963, British Foreign Secretary
Alec Douglas-Home, Soviet foreign minister Gromyko, and US Secretary of State
Dean Rusk signed the final agreement. ==Implementation==