Nuclear weapons tests are experiments carried out to determine the performance, yield , and effects of nuclear weapons . Testing nuclear weapons offers practical information about how the weapons function, how detonations are affected by different conditions, and how personnel, structures, and equipment are affected when subjected to nuclear explosions . However, nuclear testing has often been used as an indicator of scientific and military strength. Many tests have been overtly political in their intention; most nuclear weapons states publicly declared their nuclear status through a nuclear test.
150-401: The Partial Test Ban Treaty ( PTBT ), formally known as the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water , prohibited all test detonations of nuclear weapons except for those conducted underground . It is also abbreviated as the Limited Test Ban Treaty ( LTBT ) and Nuclear Test Ban Treaty ( NTBT ), though the latter may also refer to
300-514: A "cut-off" of fissionable-material production in a "partial" disarmament plan. The British government, then led by Macmillan, had yet to fully endorse a test ban. Accordingly, it pushed the US to demand that the production cut-off be closely timed with the testing moratorium, betting that the Soviet Union would reject this. London also encouraged the US to delay its disarmament plan, in part by moving
450-597: 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. In the same year, the British Labour Party , then led by Clement Attlee , called on the UN to ban testing of thermonuclear weapons. 1955 marks the beginning of test-ban negotiations, as Soviet leader Nikita Khrushchev first proposed talks on
600-600: A Soviet intelligence officer to settle on 15 inspections per year. This was rejected by Khrushchev. Nuclear weapons testing The first nuclear device was detonated as a test by the United States at the Trinity site in New Mexico on July 16, 1945, with a yield approximately equivalent to 20 kilotons of TNT . The first thermonuclear weapon technology test of an engineered device, codenamed Ivy Mike ,
750-544: 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,
900-467: 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. In 1954, just weeks after the Castle Bravo test, Indian Prime Minister Jawaharlal Nehru made the first public call for
1050-471: A clear nuclear advantage via regular testing and that the negative environmental impacts of such tests were overstated. Furthermore, Strauss repeatedly emphasized the risk of the Soviet Union violating a ban, a fear Eisenhower shared. On 7 November 1957, after Sputnik and under pressure to bring on a dedicated science advisor, Eisenhower created the President's Science Advisory Committee (PSAC), which had
1200-565: A cohesive test ban policy, noting his ability to "believe in two mutually contradictory and inconsistent propositions at the same time." 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
1350-608: A cutoff in nuclear production should precede a test ban. In the summer of 1957, Khrushchev was at acute risk of losing power, as the Anti-Party Group composed of former Stalin allies Lazar Kaganovich , Georgy Malenkov , and Vyacheslav Molotov launched an attempt to replace Khrushchev as General Secretary of the Communist Party (effectively the leader of the Soviet Union) with Nikolai Bulganin , then
1500-487: A given weapon type for a country is included, as well as tests that were otherwise notable (such as the largest test ever). All yields (explosive power) are given in their estimated energy equivalents in kilotons of TNT (see TNT equivalent ). Putative tests (like Vela incident ) have not been included. Acheson%E2%80%93Lilienthal Report The Report on the International Control of Atomic Energy
1650-412: A halt to nuclear weapons production (the one-time US demand). In explaining the policy shift, Eisenhower privately said that continued resistance to a test ban would leave the US in a state of "moral isolation." On 8 April 1958, still resisting Khrushchev's call for a moratorium, Eisenhower invited the Soviet Union to join these technical negotiations in the form of a conference on the technical aspects of
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#17327649697051800-433: 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
1950-518: A limit Eisenhower would revise upward in May 1959—would be banned first, with negotiations on underground and outer-space tests continuing. This proposal was turned down on 23 April 1959 by Khrushchev, calling it a "dishonest deal." On 26 August 1959, the US announced it would extend its year-long testing moratorium to the end of 1959, and would not conduct tests after that point without prior warning. The Soviet Union reaffirmed that it would not conduct tests if
2100-533: A new US proposal by which only tests deemed verifiable by the Geneva System would be banned, including all atmospheric, underwater, and outer-space tests within detection range. Underground tests measuring more than 4.75 on the Richter scale would also be barred, subject to revision as research on detection continued. Adopting Macmillan's quota compromise, the US proposed each nuclear state be subject to roughly 20 on-site inspections per year (the precise figure based on
2250-506: A number of populated islands in nearby atoll formations. Though they were soon evacuated, many of the islands' inhabitants suffered from radiation burns and later from other effects such as increased cancer rate and birth defects, as did the crew of the Japanese fishing boat Daigo Fukuryū Maru . One crewman died from radiation sickness after returning to port, and it was feared that the radioactive fish they had been carrying had made it into
2400-428: 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
2550-585: A precursor to a test ban. On 1 July 1958, responding to Eisenhower's call, the nuclear powers convened the Conference of Experts in Geneva , aimed at studying means of detecting nuclear tests. The conference included scientists from the US, Britain, the Soviet Union, Canada, Czechoslovakia, France, Poland, and Romania. The US delegation was led by James Fisk, a member of PSAC, the Soviets by Evgenii Fedorov, and
2700-532: A result of a scenario of a concentrated number of nuclear explosions in a nuclear holocaust , the thousands of tests, hundreds being atmospheric, did nevertheless produce a global fallout that has peaked in 1963 (the Bomb pulse ), reaching levels of about 0.15 mSv per year worldwide, or about 7% of average background radiation dose from all sources, and has slowly decreased since, with natural environmental radiation levels being around 1 mSv . This global fallout
2850-505: 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. On 13 April 1959, facing Soviet opposition to on-site detection systems for underground tests, Eisenhower proposed moving from a single, comprehensive test ban to a graduated agreement where atmospheric tests—those up to 50 km (31 mi) high,
3000-474: A scheme would be able to detect 90% of underground detonations, accurate to 5 kilotons, and atmospheric tests with a minimum yield of 1 kiloton. The US had initially advocated for 650 posts, versus a Soviet proposal of 100–110. The final recommendation was a compromise forged by the British delegation. In a widely publicized and well-received communiqué dated 21 August 1958, the conference declared that it "reached
3150-404: 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. Lewis Strauss and Edward Teller , dubbed the "father of the hydrogen bomb," 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
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#17327649697053300-555: 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( JFK ) 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 ,
3450-473: A single salvo test; Pakistan's second and last official test exploded four different devices. Almost all lists in the literature are lists of tests; in the lists in Misplaced Pages (for example, Operation Cresset has separate items for Cremino and Caerphilly , which together constitute a single test), the lists are of explosions. Separately from these designations, nuclear tests are also often categorized by
3600-564: A temporary basis (a duration of roughly 1 year, versus the Soviet proposal of 4–5 years), but this could only happen after verifiable tests had been banned and a seismic research group (the Seismic Research Program Advisory Group) convened. The Soviet Union responded positively to the counterproposal and the research group convened on 11 May 1960. The Soviet Union also offered to keep an underground ban out of
3750-532: 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 advocacy of PSAC, including that of its chairmen James Rhyne Killian and George Kistiakowsky , was a key factor in Eisenhower's eventual decision to initiate test-ban negotiations in 1958. In
3900-481: A test ban in 1958. There was also increased environmental concern in the Soviet Union. In the mid-1950s, Soviet scientists began taking regular radiation readings near Leningrad , Moscow , and Odessa and collected data on the prevalence of strontium-90, which indicated that strontium-90 levels in western Russia approximately matched those in the eastern US. Rising Soviet concern was punctuated in September 1957 by
4050-525: A test ban in the late 1950s. The proliferation of thermonuclear weapons coincided with a rise in public concern about nuclear fallout debris contaminating food sources, particularly the threat of high levels of strontium-90 in milk (see the Baby Tooth Survey ). This survey was a scientist and citizen led campaign which used "modern media advocacy techniques to communicate complex issues" to inform public discourse. Its research findings confirmed
4200-560: A test ban. The British governments of 1954–58 (under Conservatives Winston Churchill , Anthony Eden , and Harold Macmillan ) also quietly resisted a test ban, despite the British public favoring a deal, until the US Congress approved expanded nuclear collaboration in 1958 and until after Britain had tested its first hydrogen bombs . In their view, testing was necessary if the UK nuclear program were to continue to develop. This opposition
4350-442: A test-ban, specifically the technical details of ensuring compliance with a ban. The proposal was, to a degree, a concession to the Soviet Union, as a test ban would be explored independent of the previously demanded cutoff in fissionable-material production. Khrushchev initially declined the invitation, but eventually agreed "in spite of the serious doubts" he had after Eisenhower suggested a technical agreement on verification would be
4500-473: A testing series and the US was about to begin Operation Hardtack I , a series of atmospheric, surface-level, and underwater nuclear tests. Eisenhower instead insisted that any moratorium be linked to reduced production of nuclear weapons. In April 1958, the US began Operation Hardtack I as planned. The Soviet declaration concerned the British government, which feared that the moratorium might lead to
4650-447: A variety of fissile material compositions, densities, shapes, and reflectors . They can be subcritical or supercritical, in which case significant radiation fluxes can be produced. This type of test has resulted in several criticality accidents . Subcritical (or cold) tests are any type of tests involving nuclear materials and possibly high explosives (like those mentioned above) that purposely result in no yield . The name refers to
Partial Nuclear Test Ban Treaty - Misplaced Pages Continue
4800-488: Is very unlikely to develop significant nuclear innovations without testing. One other approach is to use supercomputers to conduct "virtual" testing, but codes need to be validated against test data. There have been many attempts to limit the number and size of nuclear tests; the most far-reaching is the Comprehensive Test Ban Treaty of 1996, which has not, as of 2013 , been ratified by eight of
4950-551: The Comprehensive Nuclear-Test-Ban Treaty (CTBT), which succeeded the PTBT for ratifying parties. Negotiations initially focused on a comprehensive ban, but that was abandoned because of technical questions surrounding the detection of underground tests and Soviet concerns over the intrusiveness of proposed verification methods. The impetus for the test ban was provided by rising public anxiety over
5100-530: The Kyshtym disaster , which forced the evacuation of 10,000 people after an explosion at a nuclear plant. Around the same time, 219 Soviet scientists signed Pauling's antinuclear petition. Soviet political elites did not share the concerns of others in the Soviet Union. However; Kurchatov unsuccessfully called on Khrushchev to halt testing in 1958. On 14 June 1957, following Eisenhower's suggestion that existing detection measures were inadequate to ensure compliance,
5250-631: The Premier of the Soviet Union . The attempted ouster, which was foiled in June, was followed by a series of actions by Khrushchev to consolidate power. In October 1957, still feeling vulnerable from Anti-Party Group's ploy, Khrushchev forced out defense minister Georgy Zhukov , cited as "the nation's most powerful military man." On 27 March 1958, Khrushchev forced Bulganin to resign and succeeded him as Premier. Between 1957 and 1960, Khrushchev had his firmest grip on power, with little real opposition. Khrushchev
5400-469: The Supreme Soviet of the Soviet Union approved a decision to halt nuclear testing, conditional on other nuclear powers doing the same. Khrushchev then called on Eisenhower and Macmillan to join the moratorium. Despite the action being met with widespread praise and an argument from Dulles that the US should reciprocate, Eisenhower dismissed the plan as a "gimmick"; the Soviet Union had just completed
5550-524: The Vela incident . From the first nuclear test in 1945 until tests by Pakistan in 1998, there was never a period of more than 22 months with no nuclear testing. June 1998 to October 2006 was the longest period since 1945 with no acknowledged nuclear tests. A summary table of all the nuclear testing that has happened since 1945 is here: Worldwide nuclear testing counts and summary . While nuclear weapons testing did not produce scenarios like nuclear winter as
5700-575: The atomic bombing of Hiroshima visited the US for medical care, which attracted significant public attention. In 1961, the Soviet Union tested the Tsar Bomba , which had a yield of 50 megatons and remains the most powerful man-made explosion in history, though due to a highly efficient detonation fallout was relatively limited. Between 1951 and 1958, the US conducted 166 atmospheric tests, the Soviet Union conducted 82, and Britain conducted 21; only 22 underground tests were conducted in this period (all by
5850-433: The atomic bombs that had been tested and deployed since the Trinity test in 1945. In 1954, the U.S. conducted the Castle Bravo test at Bikini Atoll as part of Operation Castle , which resulted in a yield of 15 megatons of TNT , more than double the expected yield. This unexpectedly high yield caused widespread radioactive fallout, leading to severe environmental and human consequences. The Castle Bravo test resulted in
6000-474: The " Annex 2 countries " required for it to take effect, including the United States. Nuclear testing has since become a controversial issue in the United States, with a number of politicians saying that future testing might be necessary to maintain the aging warheads from the Cold War . Because nuclear testing is seen as furthering nuclear arms development, many are opposed to future testing as an acceleration of
6150-465: 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
Partial Nuclear Test Ban Treaty - Misplaced Pages Continue
6300-461: The 21 August communiqué. Nevertheless, pleased by the findings, the Eisenhower administration proposed negotiations on a permanent test ban and announced it would self-impose a year-long testing moratorium if Britain and the Soviet Union did the same. This decision amounted to a victory for John Foster Dulles, Allen Dulles (then the Director of Central Intelligence ), and PSAC, who had argued within
6450-655: The Anglo-American plan were unacceptable to Tsarapkin, who responded with separate proposals rejected by the Western powers. Specifically, the Soviet Union proposed a "troika" mechanism: a monitoring board composed of representatives of the West, the Soviet Union, and nonaligned states that would require unanimity before acting (effectively giving the Soviet Union veto authority). In May 1961, Kennedy attempted via secret contact between Attorney General Robert F. Kennedy and
6600-578: 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
6750-501: The British delegation by William Penney , who had led the British delegation to the Manhattan Project. Whereas the US approached the conference solely from a technical perspective, Penney was specifically instructed by Macmillan to attempt to achieve a political agreement. This difference in approach was reflected in the broader composition of the US and UK teams. US experts were primarily drawn from academia and industry. Fisk
6900-539: The CTBT has been signed by 183 States, of which 157 have also ratified. However, for the Treaty to enter into force it needs to be ratified by 44 specific nuclear technology-holder countries. These "Annex 2 States" participated in the negotiations on the CTBT between 1994 and 1996 and possessed nuclear power or research reactors at that time. The ratification of eight Annex 2 states is still missing: China, Egypt, Iran, Israel and
7050-469: 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
7200-476: The Discontinuance of Nuclear Tests) and agreed to a temporary moratorium (the Soviet Union joined the moratorium shortly after this date). 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
7350-504: The Eisenhower administration for separating a test ban from larger disarmament efforts, and a defeat for the Department of Defense and AEC, which had argued to the contrary. In May 1958, Britain had informed the US that it would be willing to join a testing moratorium on 31 October 1958, by which point it would have finished its hydrogen-bomb testing, conditional on the US providing Britain with nuclear information following amendment of
7500-600: The Japanese food supply. Castle Bravo was the worst U.S. nuclear accident, but many of its component problems—unpredictably large yields, changing weather patterns, unexpected fallout contamination of populations and the food supply—occurred during other atmospheric nuclear weapons tests by other countries as well. Concerns over worldwide fallout rates eventually led to the Partial Test Ban Treaty in 1963, which limited signatories to underground testing. Not all countries stopped atmospheric testing, but because
7650-586: The Joint Committee on Atomic Energy, argued that the Soviet system would be unable to prevent secret tests. That year, the AEC published a report arguing that the continuing testing moratorium risked "free world supremacy in nuclear weapons," and that renewed testing was critical for further weapons development. The joint committee also held hearings in April which cast doubt on the technical feasibility and cost of
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#17327649697057800-572: The Macmillan–Eisenhower proposal. But US-Soviet relations soured after an American U-2 spy plane was shot down in Soviet airspace in May 1960. The Paris summit was abruptly cancelled and the Soviet Union withdrew from the seismic research group, which subsequently dissolved. Meetings of the Geneva Conference continued until December, but little progress was made as Western-Soviet relations continued to grow more antagonistic through
7950-741: 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
8100-479: The McMahon Act. The US Congress approved amendments permitting greater collaboration in late June. Following Soviet assent on 30 August 1958 to the one-year moratorium, the three countries conducted a series of tests in September and October. At least 54 tests were conducted by the US and 14 by the Soviet Union in this period. On 31 October 1958 the three countries initiated test-ban negotiations (the Conference on
8250-701: The Partial Nuclear Test Ban Treaty. The 1996 Comprehensive Nuclear-Test-Ban Treaty (CTBT) bans all nuclear explosions everywhere, including underground. For that purpose, the Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization is building an international monitoring system with 337 facilities located all over the globe. 85% of these facilities are already operational. As of May 2012 ,
8400-455: 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
8550-426: The Soviet Union as "both powerful and responsible." At the 20th Communist Party Congress in 1956, Khrushchev declared that nuclear war should no longer be seen as "fatalistically inevitable." Simultaneously, however, Khrushchev expanded and advanced the Soviet nuclear arsenal at a cost to conventional Soviet forces (e.g., in early 1960, Khrushchev announced demobilization of 1.2 million troops). On 31 March 1958,
8700-408: The Soviet Union but still insisting that the Soviets should agree not to develop the bomb. Those were modifications that neither Acheson nor Lilienthal accepted. That, combined with US continued insistence on retaining the bomb until it was satisfied with the effectiveness of international control, ultimately led to the plan's rejection by the Soviets to the surprise of no one. The consultants heading
8850-478: The Soviet Union insisted that the inspection quota be determined on a political basis, not a scientific one. The Soviet offer faced a mixed reception. In the US, Senator Hubert Humphrey and the Federation of American Scientists (which was typically seen as supportive of a test ban) saw it as a clear step towards an agreement. Conversely, AEC chairman John A. McCone and Senator Clinton Presba Anderson , chair of
9000-448: The Soviet Union privately suggested it would accept a quota of three inspections per year. The US argued that the quota should be set according to scientific necessity (i.e., be set according to the frequency of seismic events). In June 1959, a report of a panel headed by Lloyd Berkner , a physicist, was introduced into discussions by Wadsworth. The report specifically concerned whether the Geneva System could be improved without increasing
9150-427: The Soviet Union put forth a plan for a two-to-three-year testing moratorium. The moratorium would be overseen by an international commission reliant on national monitoring stations, but, importantly, would involve no on-the-ground inspections. Eisenhower initially saw the deal as favorable, but eventually came to see otherwise. In particular, Strauss and Teller, as well as Ernest Lawrence and Mark Muir Mills , protested
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#17327649697059300-437: 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
9450-540: 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
9600-623: The US While the test ban was not a focus on conversations, a positive meeting with Eisenhower at Camp David eventually led Tsarapkin to propose a technical working group in November 1959 that would consider the issues of on-site inspections and seismic decoupling in the "spirit of Camp David." Within the working group, Soviet delegates allowed for the timing of on-site inspections to be grounded in seismic data, but insisted on conditions that were seen as excessively strict. The Soviets also recognized
9750-635: The US and UK continued to observe a moratorium. To break the deadlock over verification, Macmillan proposed a compromise in February 1959 whereby each of the original parties would be subject to a set number of on-site inspections each year. In May 1959, Khrushchev and Eisenhower agreed to explore Macmillan's quota proposal, though Eisenhower made further test-ban negotiations conditional on the Soviet Union dropping its Control Commission veto demand and participating in technical discussions on identification of high-altitude nuclear explosions . Khrushchev agreed to
9900-427: The US assented to a two-year testing moratorium proposed by the Soviet Union, but required that it be linked to restrictions on the production of fissionable material with military uses, a condition that the Soviet Union rejected. While Eisenhower insisted on linking a test ban to a broader disarmament effort (e.g., the production cut-off), Moscow insisted on independent consideration of a test ban. On 19 September 1957,
10050-507: The US conducted the first contained underground test at the Nevada Test Site , codenamed Rainier . The Rainier shot complicated the push for a comprehensive test ban, as underground tests could not be as easily identified as atmospheric tests. Despite Eisenhower's interest in a deal, his administration was hamstrung by discord among US scientists, technicians, and politicians. At one point, Eisenhower complained that "statecraft
10200-430: 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 ,
10350-564: 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,
10500-423: The US would not be held to its testing moratorium when it expired on 31 December 1959, though pledged to not test if Geneva talks progressed. The Soviet Union followed by reiterating its decision to not test as long as Western states did not test. In early 1960, Eisenhower indicated his support for a comprehensive test ban conditional on proper monitoring of underground tests. On 11 February 1960, Wadsworth announced
10650-600: The US). 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
10800-804: The United Kingdom until 1991, the United States until 1992, and both China and France until 1996. In signing the Comprehensive Nuclear-Test-Ban Treaty in 1996, these countries pledged to discontinue all nuclear testing; the treaty has not yet entered into force because of its failure to be ratified by eight countries. Non-signatories India and Pakistan last tested nuclear weapons in 1998. North Korea conducted nuclear tests in 2006 , 2009 , 2013 , January 2016 , September 2016 and 2017. The most recent confirmed nuclear test occurred in September 2017 in North Korea. Nuclear weapons tests have historically been divided into four categories reflecting
10950-503: The United States and the Soviet Union were responsible for roughly 86% of all nuclear tests, their compliance cut the overall level substantially. France continued atmospheric testing until 1974, and China until 1980. A tacit moratorium on testing was in effect from 1958 to 1961 and ended with a series of Soviet tests in late 1961, including the Tsar Bomba , the largest nuclear weapon ever tested. The United States responded in 1962 with Operation Dominic , involving dozens of tests, including
11100-457: The United States have signed but not ratified the Treaty; India, North Korea and Pakistan have not signed it. The following is a list of the treaties applicable to nuclear testing: Over 500 atmospheric nuclear weapons tests were conducted at various sites around the world from 1945 to 1980. As public awareness and concern mounted over the possible health hazards associated with exposure to the nuclear fallout , various studies were done to assess
11250-425: The West. The proposal would serve as the basis of the Soviet negotiating position through 1957. Eisenhower had supported nuclear testing after World War II . In 1947, he rejected arguments by Stafford L. Warren , the Manhattan Project's chief physician, concerning the detrimental health effects of atmospheric testing, agreeing instead with James Bryant Conant , a chemist and participant in the Manhattan Project, who
11400-409: The amount of it that is necessary. Hydronuclear tests study nuclear materials under the conditions of explosive shock compression. They can create subcritical conditions, or supercritical conditions with yields ranging from negligible all the way up to a substantial fraction of full weapon yield. Critical mass experiments determine the quantity of fissile material required for criticality with
11550-417: The arms race. In total nuclear test megatonnage , from 1945 to 1992, 520 atmospheric nuclear explosions (including eight underwater) were conducted with a total yield of 545 megatons , with a peak occurring in 1961–1962, when 340 megatons were detonated in the atmosphere by the United States and Soviet Union , while the estimated number of underground nuclear tests conducted in the period from 1957 to 1992
11700-586: The atmosphere. The PTBT was signed by the governments of the Soviet Union , the United Kingdom , and the United States in Moscow on 5 August 1963 before it was opened for signature by other countries. The treaty formally went into effect on 10 October 1963. Since then, 123 other states have become party to the treaty. Ten states have signed but not ratified the treaty. The primary motivation for
11850-577: The beginning of the Report embodies the comments that Acheson's Committee made on the unanimous findings and recommendations of the Board of Consultants. The other members of the committee were scientists James Conant and Vannevar Bush , the director of the Office of Scientific Research and Development , which controlled the Manhattan Project , and John McCloy , and General Leslie R. Groves , who had been
12000-501: The bomb ostentatiously in reserve but to negotiate with the Soviet Union not to develop one would simply drive the Soviets into developing their own weapon to restore the balance of power. The other school included men like Secretary of State James F. Byrnes , who felt that the US monopoly on atomic weapons had been honestly earned and should not be surrendered. In their view, the Soviets understood only power, which could be met only with nuclear weapons. President Harry S. Truman
12150-482: The burial points of all explosive devices can be connected by segments of straight lines, each of them connecting two burial points, and the total length does not exceed 40 kilometers. For nuclear weapon tests, a salvo is defined as two or more underground nuclear explosions conducted at a test site within an area delineated by a circle having a diameter of two kilometers and conducted within a total period of time of 0.1 seconds. The USSR has exploded up to eight devices in
12300-450: The closeness of the Soviet proposal to earlier Western proposals, the US reversed its position on the provisions and rejected the Soviet offer "in the absence of more general control agreements," including limits on the production of fissionable material and protections against a surprise nuclear strike . The May 1955 proposal is now seen as evidence of Khrushchev's "new approach" to foreign policy, as Khrushchev sought to mend relations with
12450-583: 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 complication verification provisions as US scientists, including Hans Bethe (who backed
12600-432: The complex technical questions of a test ban, driven in part by a strong interest among American experts to lower the error rate of seismic test detection technology. Some, including Kistiakowsky, would eventually raise concerns about the ability of inspections and monitors to successfully detect tests. The primary product of negotiations under Eisenhower was the testing moratorium without any enforcement mechanism. Ultimately,
12750-452: The conclusion that it is technically feasible to set up ... a workable and effective control system for the detection of violations of a possible agreement on the worldwide cessation of nuclear weapons tests." The technical findings, released on 30 August 1958 in a report drafted by the Soviet delegation, were endorsed by the US and UK, which proposed that they serve as the basis for test-ban and international-control negotiations. However,
12900-441: The conference. At particular issue was the ability of sensors to differentiate an underground test from an earthquake. There were four techniques examined: measurement of acoustic waves , seismic signals, radio waves , and inspection of radioactive debris. The Soviet delegation expressed confidence in each method, while Western experts argued that a more comprehensive compliance system would be necessary. The Conference of Experts
13050-508: 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 . In the spring of 1957, the US National Security Council had explored including a one-year test moratorium and
13200-561: The control of atomic energy to a United Nations Atomic Energy Commission was endorsed by both the Americans and the Soviets in 1945. They had the forum, but the United States had not yet articulated a policy that it wished the new commission to adopt. To resolve the problem, Acheson was appointed to head a committee to determine US policy on atomic energy, the Committee on Atomic Energy, set up on January 7, 1946. A letter of transmittal at
13350-410: 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
13500-552: The development of additional atomic bombs. This was to prove too controversial. Although Truman accepted the report in general, his appointment of financier Bernard Baruch to carry the proposal forward in the United Nations led to demands for punishment for violations and that those penalties could not be vetoed by the United Nations Security Council , as well as unrestricted inspections within
13650-546: The discord within American circles, particularly among scientists, was made clear in hearings before the Senate Subcommittee on Nuclear Disarmament, chaired by Senator Hubert Humphrey . The hearings featured conflicting testimony from the likes of Teller and Linus Pauling, as well as from Harold Stassen, who argued that a test ban could safely be separated from broader disarmament, and AEC members, who argued that
13800-411: The effect of eroding the AEC's monopoly over scientific advice. In stark contrast to the AEC, PSAC promoted a test ban and argued against Strauss's claims concerning its strategic implications and technical feasibility. In late 1957, the Soviet Union made a second offer of a three-year moratorium without inspections, but lacking any consensus within his administration, Eisenhower rejected it. In early 1958,
13950-520: The experts' report failed to address precisely who would do the monitoring and when on-site inspections—a US demand and Soviet concern—would be permitted. The experts also deemed detection of outer-space tests (tests more than 50 kilometers (31 mi) above the earth's surface) to be impractical. Additionally, the size of the Geneva System may have rendered it too expensive to be put into effect. The 30 August report, which contained details on these limitations, received significantly less public attention than
14100-719: The explosion of a missile launched from a submarine. Almost all new nuclear powers have announced their possession of nuclear weapons with a nuclear test. The only acknowledged nuclear power that claims never to have conducted a test was South Africa (although see Vela incident ), which has since dismantled all of its weapons. Israel is widely thought to possess a sizable nuclear arsenal, though it has never tested, unless they were involved in Vela. Experts disagree on whether states can have reliable nuclear arsenals—especially ones using advanced warhead designs, such as hydrogen bombs and miniaturized weapons—without testing, though all agree that it
14250-441: The explosion's effects, it did not give an appreciable understanding of nuclear fallout , which was not well understood by the project scientists until well after the atomic bombings of Hiroshima and Nagasaki . The United States conducted six atomic tests before the Soviet Union developed their first atomic bomb ( RDS-1 ) and tested it on August 29, 1949. Neither country had very many atomic weapons to spare at first, and so testing
14400-405: The extent of the hazard. A Centers for Disease Control and Prevention / National Cancer Institute study claims that nuclear fallout might have led to approximately 11,000 excess deaths, most caused by thyroid cancer linked to exposure to iodine-131 . The following list is of milestone nuclear explosions. In addition to the atomic bombings of Hiroshima and Nagasaki , the first nuclear test of
14550-552: The formation of these treaties. Examples can be seen in the following articles: The Partial Nuclear Test Ban treaty makes it illegal to detonate any nuclear explosion anywhere except underground, in order to reduce atmospheric fallout. Most countries have signed and ratified the Partial Nuclear Test Ban, which went into effect in October 1963. Of the nuclear states, France, China, and North Korea have never signed
14700-538: The frequency of seismic events). Tsarapkin responded positively to the US proposal, though was wary of the prospect of allowing underground tests registering below magnitude 4.75. In its own proposal offered 19 March 1960 the Soviet Union accepted most US provisions, with certain amendments. First, the Soviet Union asked that underground tests under magnitude 4.75 be banned for a period of four-to-five years, subject to extension. Second, it sought to prohibit all outer-space tests, whether within detection range or not. Finally,
14850-424: 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
15000-491: The lack of creation of a critical mass of fissile material. They are the only type of tests allowed under the interpretation of the Comprehensive Nuclear-Test-Ban Treaty tacitly agreed to by the major atomic powers. Subcritical tests continue to be performed by the United States, Russia, and the People's Republic of China, at least. Subcritical tests executed by the United States include: The first atomic weapons test
15150-409: The later phases of the Cold War , though, both countries developed accelerated testing programs, testing many hundreds of bombs over the last half of the 20th century. Atomic and nuclear tests can involve many hazards. Some of these were illustrated in the U.S. Castle Bravo test in 1954. The weapon design tested was a new form of hydrogen bomb, and the scientists underestimated how vigorously some of
15300-459: The latter and was noncommittal on the former. A working group in Geneva would eventually devise a costly system of 5–6 satellites orbiting at least 18,000 miles (29,000 km) above the earth, though it could not say with certainty that such a system would be able to determine the origin of a high-altitude test. US negotiators also questioned whether high-altitude tests could evade detection via radiation shielding . Concerning Macmillan's compromise,
15450-416: 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
15600-501: The limited arms-control suggestion of Nehru, whose proposal for a test ban was discarded by the National Security Council for being "not practical." Harold Stassen , Eisenhower's special assistant for disarmament, argued that the US should prioritize a test ban as a first step towards comprehensive arms control, conditional on the Soviet Union accepting on-site inspections, over full disarmament. Stassen's suggestion
15750-400: The magnitude of nuclear tests, particularly tests of new thermonuclear weapons (hydrogen bombs), and the resulting nuclear fallout . A test ban was also seen as a means of slowing nuclear proliferation and the nuclear arms race . Though the PTBT did not halt proliferation or the arms race, its enactment did coincide with a substantial decline in the concentration of radioactive particles in
15900-455: The medium or location of the test. Another way to classify nuclear tests is by the number of explosions that constitute the test. The treaty definition of a salvo test is: In conformity with treaties between the United States and the Soviet Union, a salvo is defined, for multiple explosions for peaceful purposes, as two or more separate explosions where a period of time between successive individual explosions does not exceed 5 seconds and where
16050-520: The military effects of atomic weapons ( Crossroads had involved the effect of atomic weapons on a navy, and how they functioned underwater) and to test new weapon designs. During the 1950s, these included new hydrogen bomb designs, which were tested in the Pacific, and also new and improved fission weapon designs. The Soviet Union also began testing on a limited scale, primarily in Kazakhstan . During
16200-511: The military officer in charge of the Manhattan Project. Acheson decided that the committee needed technical advice and so he appointed a board of consultants with David Lilienthal , the well-regarded chairman of the Tennessee Valley Authority , as chairman. He also appointed J. Robert Oppenheimer , scientific leader of the Manhattan Project, who provided influential advice. Oppenheimer's contribution lay in an idea to police
16350-541: The number of control posts. Berkner's proposed measures were seen as highly costly and the technical findings themselves were accompanied by a caveat about the panel's high degree of uncertainty given limited data. Around the same time, analysis conducted by the Livermore National Laboratory and RAND Corporation at Teller's instruction found that the seismic effect of an underground test could be artificially dampened (referred to as "decoupling") to
16500-498: The offer. At a meeting with Eisenhower in the White House, the group argued that testing was necessary for the US to eventually develop bombs that produced no fallout ("clean bombs"). The group repeated the oft-cited fact, which was supported by Freeman Dyson , 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
16650-448: The point that a 300-kiloton detonation would appear in seismic readings as a one-kiloton detonation. These findings were largely affirmed by pro-ban scientists, including Bethe. The third blow to the verification negotiations was provided by a panel chaired by Robert Bacher, which found that even on-site inspections would have serious difficulty determining whether an underground test had been conducted. In September 1959, Khrushchev visited
16800-618: 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." The Soviet Union dismissed
16950-566: The production of atomic weapons from monitoring source mines for uranium . On March 16, 1946, the committee's report was presented to the State Department , which released it to the public on March 28. The Report on the International Control of Atomic Energy soon became known as the Acheson–Lilienthal Report . The primary message of the report was that control of atomic energy through inspections and policing operations
17100-510: The project comprised Chester Barnard , J. Robert Oppenheimer , Charles A. Thomas , Harry A. Winne, and David E. Lilienthal , while the official authors, who had worked on the Manhattan Project and included some of the United States' top scientists, comprised Luis Walter Alvarez , Robert F. Bacher , Manson Benedict , Hans Bethe , Arthur Compton , Farrington Daniels , J. Robert Oppenheimer, John R. Ruhoff, G. T. Seaborg , Frank Spedding , Charles A. Thomas, and Walter Zinn . The report itself
17250-561: 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
17400-506: The proposed verification measures. Additionally, Teller continued to warn of the dangerous consequences of a test ban and the Department of Defense (including Neil H. McElroy and Donald A. Quarles , until recently its top two officials) pushed to continue testing and expand missile stockpiles. Shortly after the Soviet proposal, Macmillan met with Eisenhower at Camp David to devise a response. The Anglo-American counterproposal agreed to ban small underground tests (those under magnitude 4.75) on
17550-528: The purpose of the test itself. Aside from these technical considerations, tests have been conducted for political and training purposes, and can often serve multiple purposes. Computer simulation is used extensively to provide as much information as possible without physical testing. Mathematical models for such simulation model scenarios not only of performance but also of shelf life and maintenance . A theme has generally been that even though simulations cannot fully replace physical testing, they can reduce
17700-495: 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
17850-515: The spring of 1958, chairman Killian and the PSAC staff (namely Hans Bethe and Isidor Isaac Rabi ) undertook a review of US test-ban policy, determining that a successful system for detecting underground tests could be created. At the recommendation of Dulles (who had recently come to support a test ban), the review prompted Eisenhower to propose technical negotiations with the Soviet Union, effectively detaching test-ban negotiations from negotiations over
18000-595: The start of the moratorium back to November 1958. At the same time, Macmillan linked British support for a test ban to a revision of the Atomic Energy Act of 1946 (McMahon Act), which prohibited sharing of nuclear information with foreign governments. Eisenhower, eager to mend ties with Britain following the Suez Crisis of 1956, was receptive to Macmillan's conditions, but the AEC and the congressional Joint Committee on Atomic Energy were firmly opposed. It
18150-490: The subject in February 1955. On 10 May 1955, the Soviet Union proposed a test ban before the UN Disarmament Commission's "Committee of Five" (Britain, Canada , France , the Soviet Union, and the US). This proposal, which closely reflected a prior Anglo-French proposal, was initially part of a comprehensive disarmament proposal meant to reduce conventional arms levels and eliminate nuclear weapons. Despite
18300-596: The summer, punctuated by the Congo Crisis in July and angry exchanges at the UN in September. Macmillan would later claim to President John F. Kennedy that the failure to achieve a test ban in 1960 "was all the fault of the American 'big hole' obsession and the consequent insistence on a wantonly large number of on-site inspections." Eisenhower would leave office with an agreement out of reach, as Eisenhower's technical advisors, upon whom he relied heavily, became mired in
18450-400: 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,
18600-511: The then four nuclear states and many non-nuclear states signed the Limited Test Ban Treaty , pledging to refrain from testing nuclear weapons in the atmosphere, underwater, or in outer space . The treaty permitted underground nuclear testing . France continued atmospheric testing until 1974, and China continued until 1980. Neither has signed the treaty. Underground tests conducted by the Soviet Union continued until 1990,
18750-491: The theory behind decoupling, but dismissed its practical applications. The working group closed in December with no progress and significant hostility. Eisenhower issued a statement blaming "the recent unwillingness of the politically guided Soviet experts to give serious scientific consideration to the effectiveness of seismic techniques for the detection of underground nuclear explosions." Eisenhower simultaneously declared that
18900-462: The treaty stemmed from growing public concern over radioactive fallout from above-ground and underwater nuclear testing, especially as the power of nuclear devices continued to increase. Additionally, there was widespread apprehension about the broader environmental damage caused by such testing. In 1952–53, both the United States and the Soviet Union detonated their first thermonuclear weapons (hydrogen bombs), which were significantly more powerful than
19050-513: The treaty under negotiation. In May 1960, there were high hopes that an agreement would be reached at an upcoming summit of Eisenhower, Khrushchev, Macmillan, and Charles de Gaulle of France in Paris. A test ban seemed particularly close in 1960, with Britain and France in accord with the US (though France conducted its first nuclear test in February) and the Soviet Union having largely accepted
19200-455: The weapon materials would react. As a result, the explosion—with a yield of 15 Mt —was over twice what was predicted. Aside from this problem, the weapon also generated a large amount of radioactive nuclear fallout , more than had been anticipated, and a change in the weather pattern caused the fallout to spread in a direction not cleared in advance. The fallout plume spread high levels of radiation for over 100 miles (160 km), contaminating
19350-475: The worst radiological event in US history as radioactive particles spread over more than 11,000 square kilometers (4,200 sq mi), affected inhabited areas (including Rongelap Atoll and Utirik Atoll ), and sickened Japanese fishermen aboard the Lucky Dragon upon whom "ashes of death" had rained. In the same year, a Soviet test sent radioactive particles over Japan. Around the same time, victims of
19500-493: Was 1,352 explosions with a total yield of 90 Mt. The yields of atomic bombs and thermonuclear are typically measured in different amounts. Thermonuclear bombs can be hundreds or thousands of times stronger than their atomic counterparts. Due to this, thermonuclear bombs' yields are usually expressed in megatons which is about the equivalent of 1,000,000 tons of TNT. In contrast, atomic bombs' yields are typically measured in kilotons, or about 1,000 tons of TNT. In US context, it
19650-423: Was a vice president at Bell Telephone Laboratories and was joined by Robert Bacher and Ernest Lawrence, both physicists who had worked on the Manhattan Project. Conversely, British delegates largely held government positions. The Soviet delegation was composed primarily of academics, though virtually all of them had some link to the Soviet government. The Soviets shared the British goal of achieving an agreement at
19800-401: Was becoming a prisoner of scientists." Until 1957, Strauss's AEC (including its Los Alamos and Livermore laboratories) was the dominant voice in the administration on nuclear affairs, with Teller's concerns over detection mechanisms also influencing Eisenhower. Unlike some others within the US scientific community, Strauss fervently advocated against a test ban, arguing that the US must maintain
19950-434: Was characterized as "highly professional" and productive. By the end of August 1958, the experts devised an extensive control program, known as the "Geneva System," involving 160–170 land-based monitoring posts, plus 10 additional sea-based monitors and occasional flights over land following a suspicious event (with the inspection plane being provided and controlled by the state under inspection). The experts determined that such
20100-414: Was conducted near Alamogordo, New Mexico, on July 16, 1945, during the Manhattan Project , and given the codename " Trinity ". The test was originally to confirm that the implosion-type nuclear weapon design was feasible, and to give an idea of what the actual size and effects of a nuclear explosion would be before they were used in combat against Japan. While the test gave a good approximation of many of
20250-405: 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
20400-759: Was decided during the Manhattan Project that yield measured in tons of TNT equivalent could be imprecise. This comes from the range of experimental values of the energy content of TNT, ranging from 900 to 1,100 calories per gram (3,800 to 4,600 kJ/g). There is also the issue of which ton to use, as short tons, long tons, and metric tonnes all have different values. It was therefore decided that one kiloton would be equivalent to 1.0 × 10 calories (4.2 × 10 kJ). The nuclear powers have conducted more than 2,000 nuclear test explosions (numbers are approximate, as some test results have been disputed): There may also have been at least three alleged but unacknowledged nuclear explosions (see list of alleged nuclear tests ) including
20550-537: Was dismissed by others in the administration over fears that the Soviet Union would be able to conduct secret tests. On the advice of Dulles, Atomic Energy Commission (AEC) chairman Lewis Strauss , and Secretary of Defense Charles Erwin Wilson , Eisenhower rejected the idea of considering a test ban outside general disarmament efforts. During the 1952 and 1956 presidential elections, Eisenhower fended off challenger Adlai Stevenson , who ran in large part on support for
20700-415: Was divided between the two positions. He was distrustful of the Soviet Union but still did not want to lead the world down a path to destruction. He continued to solicit views from both sides. Stimson resigned in September 1945, and thereafter, the task of promoting his approach fell primarily on Under Secretary of State and later Secretary of State Dean Acheson . A proposal to pass the responsibility for
20850-426: Was not until after Sputnik in late 1957 that Eisenhower quickly moved to expand nuclear collaboration with the UK via presidential directives and the establishment of bilateral committees on nuclear matters. In early 1958, Eisenhower publicly stated that amendments to the McMahon Act were a necessary condition of a test ban, framing the policy shift in the context of US commitment to its NATO allies. In August 1957,
21000-720: Was one of the main drivers for the ban of nuclear weapons testing, particularly atmospheric testing. It has been estimated that by 2020 up to 2.4 million people have died as a result of nuclear weapons testing. There are many existing anti-nuclear explosion treaties, notably the Partial Nuclear Test Ban Treaty and the Comprehensive Nuclear Test Ban Treaty . These treaties were proposed in response to growing international concerns about environmental damage among other risks. Nuclear testing involving humans also contributed to
21150-431: Was personally troubled by the power of nuclear weapons and would later recount that he believed the weapons could never be used. In the mid-1950s, Khrushchev took a keen interest in defense policy and sought to inaugurate an era of détente with the West. Initial efforts to reach accords, such as on disarmament at the 1955 Geneva Summit , proved fruitless, and Khrushchev saw test-ban negotiations as an opportunity to present
21300-497: 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
21450-509: Was relatively infrequent (when the U.S. used two weapons for Operation Crossroads in 1946, they were detonating over 20% of their current arsenal). However, by the 1950s the United States had established a dedicated test site on its own territory ( Nevada Test Site ) and was also using a site in the Marshall Islands ( Pacific Proving Grounds ) for extensive atomic and nuclear testing. The early tests were used primarily to discern
21600-740: Was skeptical of Warren's then-theoretical claims. Warren's arguments were lent credence in the scientific community and public by the Castle Bravo test of 1954. Eisenhower, as president, first explicitly expressed interest in a comprehensive test ban that year, arguing before the National Security Council , "We could put [the Russians] on the spot if we accepted a moratorium ... Everybody seems to think that we're skunks, saber-rattlers and warmongers. We ought not miss any chance to make clear our peaceful objectives." Then-Secretary of State John Foster Dulles had responded skeptically to
21750-417: Was tempered by concern that resistance to a test ban might lead the US and Soviet Union to pursue an agreement without Britain having any say in the matter. Members of the Soviet military–industrial complex also opposed a test ban, though some scientists, including Igor Kurchatov , were supportive of antinuclear efforts. France, which was in the midst of developing its own nuclear weapon, also firmly opposed
21900-516: Was tested at the Enewetak Atoll in the Marshall Islands on November 1, 1952 (local date), also by the United States. The largest nuclear weapon ever tested was the Tsar Bomba of the Soviet Union at Novaya Zemlya on October 30, 1961, with the largest yield ever seen, an estimated 50–58 megatons . With the advent of nuclear technology and its increasing impact an anti-nuclear movement formed and in 1963, three (UK, US, Soviet Union) of
22050-468: Was the acquisition of sufficient fissile material. In response, the Acheson–Lilienthal Report proposed that the complete path from the uranium and thorium mines to post production be under international ownership. In addition, the report proposed that the United States abandon its monopoly on atomic weapons, revealing what it knew to the Soviet Union, in exchange for a mutual agreement against
22200-494: Was unlikely to succeed. Instead, the report proposed that all fissile material be owned by an international agency to be called the Atomic Development Authority , which would release small amounts to individual nations for the development of peaceful uses of atomic energy. In the first years of the atomic era, it was generally believed that the great obstacle facing a would-be developer of an atomic bomb
22350-407: Was vetoed by the Soviets at the United Nations . Two schools of thought concerning nuclear weapons emerged in the United States immediately after the end of World War II . One school, which had Secretary of War Henry Stimson as its chief proponent, believed that the apparent secrets of the atomic bomb were scientific in nature, and could not be monopolised forever. They further felt that to hold
22500-409: Was written by a committee chaired by Dean Acheson and David Lilienthal in 1946 and is generally known as the Acheson–Lilienthal Report or Plan . The report was an important American document that appeared just before the intensification of the early Cold War . It proposed the international control of nuclear weapons and the avoidance of future nuclear warfare . A version, the Baruch Plan ,
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