Editing Partial Nuclear Test Ban Treaty (section)

===Renewed efforts===
[[File:Kennedy and Khrushchev at Vienna Meeting - NARA - 193203.jpg|thumb|250px|[[John F. Kennedy|Kennedy]] and [[Nikita Khrushchev|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.{{sfn|Burns|Siracusa|2013|p=305}}{{sfn|Schlesinger|2002|p=304}}{{sfn|Seaborg|1981|p=30}} 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.{{sfn|Burns|Siracusa|2013|pp=306–307}}{{sfn|Seaborg|1981|p=32}} Notably, early in his presidency, [[John F. Kennedy|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([[JFK]]) remained committed to pursuing a comprehensive test ban, recognizing it as a crucial step toward curbing the nuclear arms race.{{sfn|Jacobson|Stein|1966|pp=339–341}}

On 21 March 1961, test-ban negotiations resumed in Geneva and [[Arthur Dean (lawyer)|Arthur Dean]], a lead US envoy,<ref>{{cite news |title=Arthur H. Dean, Envoy to Korea Talks, Dies at 89 |last=Krebs |first=Albin |work=The New York Times |url=https://www.nytimes.com/1987/12/01/obituaries/arthur-h-dean-envoy-to-korea-talks-dies-at-89.html?pagewanted=all |date=1 December 1987 |access-date=31 July 2016}}</ref> 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.{{sfn|Polsby|1984|p=69}} 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.<ref name=faschron/> Specifically, the Soviet Union proposed a "troika" mechanism: a monitoring board composed of representatives of the West, the Soviet Union, and [[Non-Aligned Movement|nonaligned states]] that would require unanimity before acting (effectively giving the Soviet Union veto authority).{{sfn|Polsby|1984|p=69}}{{sfn|Schlesinger|2002|pp=305–306, 369}} In May 1961, Kennedy attempted via secret contact between Attorney General [[Robert F. Kennedy]] and a Soviet intelligence officer to settle on 15 inspections per year. This was rejected by Khrushchev.{{sfn|Evangelista|1999|p=78}}

Ahead of the June 1961 [[Vienna summit]] between Kennedy and Khrushchev, Robert F. Kennedy spoke with the Soviet ambassador to the US, who suggested that progress on a test ban was possible in a direct meeting between the leaders.{{sfn|Schlesinger|2002|p=348}} President Kennedy subsequently announced to the press that he had "strong hopes" for progress on a test ban.{{sfn|Schlesinger|2002|p=356}} In Vienna, Khrushchev suggested that three inspections per year would have to be the limit, as anything more frequent would constitute [[espionage]]. Khrushchev privately believed allowing three inspections to be a significant concession to the West, as other Soviet officials preferred an even less intrusive system, and was angered by US resistance. Khrushchev later told his son, "hold out a finger to them—they chop off your whole hand."{{sfn|Evangelista|1999|p=79}}

Additionally, the Soviet Union had once been ready to support a control commission under the aegis of the UN, Khrushchev explained, but it could no longer do so given perceived bias in recent UN action in the Congo.{{sfn|Schlesinger|2002|p=369}} Instead, Khrushchev reiterated the troika proposal.{{sfn|Schlesinger|2002|pp=305–306, 369}} Furthermore, Khrushchev insisted that the test ban be considered in the context of "general and complete disarmament," arguing that a test ban on its own was unimportant; Kennedy said the US could only agree with a guarantee that a disarmament agreement would be reached quickly (the Vienna demands thus amounted to a reversal of both sides' earlier positions).{{sfn|Polsby|1984|p=69}} Kennedy also disagreed that a test ban was itself insignificant; the world could expect many more countries in the coming years to cross the nuclear threshold without a test ban. Ultimately, the two leaders left Vienna without clear progress on the subject.{{sfn|Schlesinger|2002|pp=369–370}} The Soviet Union would drop the general-disarmament demand in November 1961.<ref name=statedept/>

====Lifting the moratorium: 1961–1962====
Following setbacks at the [[Vienna Summit]] and the escalation of the [[Berlin Crisis of 1961]], as well as the [[Soviet Union]]'s decision to resume nuclear testing in August attributed by Moscow to a shifting international situation and France's nuclear tests, Kennedy faced increasing pressure from the Department of Defense and nuclear laboratories to abandon hopes of a test ban. In June 1961, after talks in Geneva had stalled, Kennedy voiced concerns that Soviet negotiating behavior posed "a serious question about how long we can safely continue on a voluntary basis a refusal to undertake tests in this country without any assurance that the Russians are not testing." Whether the Soviets had actually conducted secret tests remained a point of debate within the Kennedy administration.

A team led by physicist [[Wolfgang K. H. Panofsky]] investigated the possibility that the [[Soviet Union]] had secretly tested nuclear weapons, concluding that while such tests were possible, no evidence suggested they had occurred. Despite these findings, the [[Joint Chiefs of Staff]] dismissed Panofsky's report as "assertive, ambiguous, semiliterate, and generally unimpressive," reflecting the deep skepticism and tension within the U.S. government over Soviet activities and the broader test-ban negotiations.
"{{sfn|Burns|Siracusa|2013|p=307}}{{sfn|Schlesinger|2002|pp=455–456}}

Two weeks after the lifting of the Soviet moratorium in August 1961, and after another failed Anglo-American attempt to have the Soviet Union agree to an atmospheric-test ban, the US restarted testing on 15 September 1961. Kennedy specifically limited such testing to underground and laboratory tests, but under mounting pressure as Soviet tests continued—during the time period of the Soviet ''[[Tsar Bomba]]'' 50 Mt+ test detonation on 30 October over [[Novaya Zemlya]]—Kennedy announced and dedicated funds to a renewed atmospheric testing program in November 1961.{{sfn|Burns|Siracusa|2013|p=307}}{{sfn|Jacobson|Stein|1966|pp=343–344}}

A report on the 1961 [[Soviet]] test, published by a group of American scientists led by Hans Bethe, concluded that Soviet laboratories had likely been operating at full capacity throughout the moratorium, anticipating a resumption of testing. The report suggested that preparations for testing probably began even before the talks resumed in Geneva in March 1961. By January 1962, [[Bethe]], who had previously supported a test ban, publicly declared that a ban was "no longer a desirable goal" and advocated for the United States to conduct tests on weapons developed by its laboratories. In contrast, U.S. laboratories had been relatively inactive regarding nuclear weapons during the moratorium, highlighting a significant disparity in activity between the two nations.{{sfn|Jacobson|Stein|1966|pp=342–343}}

[[File:Hatless Jack.jpg|thumb|[[Harold Macmillan|Macmillan]] and [[John F. Kennedy|Kennedy]] in Bermuda]]
In December 1961, Macmillan met with Kennedy in [[Bermuda]], appealing for a final and permanent halt to tests. Kennedy, conversely, used the meeting to request permission to test on [[Kiritimati|Christmas Island]], with US testing grounds in the Pacific having largely been exhausted. Macmillan agreed to seek to give US permission "if the situation did not change." Christmas Island was ultimately opened to US use by February 1962.{{sfn|Jacobson|Stein|1966|pp=344–345, 347}}

On this matter of resumed atmospheric tests, Kennedy lacked the full backing of his administration and allies. In particularly, Macmillan, Adlai Stevenson (then the [[United States Ambassador to the United Nations|UN ambassador]]), the [[United States Department of State|State Department]], the [[United States Information Agency]], and [[Jerome Wiesner]], the PSAC chairman, opposed resuming atmospheric tests. On the side advocating resumption were the AEC, Joint Committee on Atomic Energy, Joint Chiefs of Staff (which had called for renewed atmospheric tests in October 1961), and Department of Defense, though then-Secretary of Defense [[Robert McNamara]] privately acknowledged that such tests were "not really necessary." Teller continued to advocate for atmospheric tests, as well, arguing in early 1962 that nuclear fallout was nothing be concerned about. Teller also argued that testing was necessary to continued advancement of US nuclear capabilities, particularly in terms of the mobility of its weapons and, accordingly, its [[second strike|second-strike capability]].{{sfn|Jacobson|Stein|1966|pp=345–346}}

Despite Teller's reassurances, Kennedy himself "hated the idea of reopening the race" and was uneasy with continued production of fallout,{{sfn|Schlesinger|2002|p=455}} a negative consequence of resumed testing that its opponents within the administration stressed. Opponents of the tests also argued that renewed atmospheric tests would come at a significant moral cost to the US, given broad public opposition to the plan, and claimed that further tests were largely unnecessary, with the US already having an adequate nuclear arsenal.{{sfn|Jacobson|Stein|1966|pp=346–347}} Arthur Dean believed that public opposition to atmospheric testing was so great that the US would have to halt such tests within four years even without an agreement.{{sfn|Strode|1990|p=33}} [[John Kenneth Galbraith]], then the [[United States Ambassador to India|ambassador to India]], had advised Kennedy in June 1961 that resumed testing "would cause us the gravest difficulties in Asia, Africa and elsewhere." Similarly, Hubert Humphrey described the moratorium as "a ray of hope to millions of worried people." Its termination, Humphrey warned, "might very well turn the political tides in the world in behalf of the Soviets."{{sfn|Schlesinger|2002|p=455}}

Ultimately, Kennedy sided with those arguing for resumed testing. In particular, an argument by William C. Foster, the head of the [[Arms Control and Disarmament Agency]], swayed Kennedy. Foster argued that if the US failed to respond to the Soviet test series, Moscow could order a second test series, which could give the Soviet Union a significant advantage. Furthermore, a second test series, without US reciprocation, could damage the push for a test ban and make [[United States Senate|Senate]] ratification of any agreement less likely.{{sfn|Jacobson|Stein|1966|pp=347–348}} On 2 March 1962, building on the November 1961 announcement, Kennedy promised to resume atmospheric testing by the end of April 1962 if Moscow continued to resist the Anglo-American test-ban proposal.<ref name=faschron/> To an extent, the announcement was a compromise, as Kennedy restricted atmospheric tests to those tests which were "absolutely necessary," not feasible underground, and minimized fallout. The condition that testing would resume only if the Soviet Union continued to oppose the Anglo-American proposal also served as a concession to dissenting voices within his administration and to Macmillan.{{sfn|Jacobson|Stein|1966|pp=347–348}}

Kennedy portrayed resumed testing as a necessary for the image of US resolve. If the US failed to respond to the Soviet test series, Kennedy explained, Moscow would "chalk it up, not to goodwill, but to a failure of will—not to our confidence in Western superiority, but to our fear of world opinion." Keeping the US in a position of strength, Kennedy argued, would be necessary for a test ban to ever come about.{{sfn|Jacobson|Stein|1966|p=349}}

The US suspension of atmospheric tests was lifted on 25 April 1962.<ref name=faschron/><ref name=cq/>

By March 1962, the trilateral talks in Geneva had shifted to 18-party talks at the UN Disarmament Conference.{{sfn|Strode|1990|pp=19–20}} On 27 August 1962, within that conference, the US and UK offered two draft treaties to the Soviet Union. The primary proposal included a comprehensive ban verified by control posts under national command, but international supervision, and required on-site inspections. This was rejected by the Soviet Union due to the inspection requirement. The alternative proposal included a partial test ban—underground tests would be excluded—to be verified by national detection mechanisms, without supervision by a supranational body.<ref name=faschron/>{{sfn|Polsby|1984|p=71}}

====Cuban Missile Crisis and beyond: 1962–1963====
In October 1962, the U.S. and [[Soviet Union]] experienced the [[Cuban Missile Crisis]], which brought the two superpowers to the brink of nuclear war. This intense standoff prompted both Kennedy and Khrushchev to seek accelerated [[rapprochement]], recognizing the urgent need to reduce tensions and prevent future confrontations.<ref name=atomicheritage/>{{sfn|Burns|Siracusa|2013|p=307}}<ref name=cuba>{{cite web |title=1963–1977: Limits on Nuclear Testing |publisher=Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization |url=https://www.ctbto.org/the-treaty/history-1945-1993/1963-77-limits-on-nuclear-testing/ |access-date=31 July 2016}}</ref><ref name=cuba2>{{cite web |title=Cuban Missile Crisis |publisher=[[John F. Kennedy Presidential Library and Museum]] |url=https://www.jfklibrary.org/learn/about-jfk/jfk-in-history/cuban-missile-crisis |access-date=31 July 2016}}</ref>{{sfn|Strode|1990|pp=23–24}}{{sfn|Evangelista|1999|p=82}} 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.<ref name=britannica>{{cite encyclopedia |title=Nuclear Test-Ban Treaty |last=Freedman |first=Lawrence D. |encyclopedia=[[Encyclopædia Britannica]] |url=https://www.britannica.com/event/Nuclear-Test-Ban-Treaty |access-date=31 July 2016}}</ref> 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.{{sfn|Burns|Siracusa|2013|p=307}}{{sfn|Evangelista|1999|p=83}} 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.{{sfn|Evangelista|1999|pp=81–82}} Khrushchev would later recount that he saw test-ban negotiations as a prime venue for ameliorating tensions after the crisis in Cuba.{{sfn|Strode|1990|p=24}}

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..<ref>Stone, Oliver and Peter Kuznick, ''The Untold History of the United States'', (Gallery Books, 2012), pp. 313–314, ''citing'' Message from Chairman Khrushchev to President Kennedy, 30 October 1962, in ''Foreign Relations of the United States, 1961–1963'', vol. 11, (Washington, DC, US Government Printing Office, 1997), pp. 309–317</ref> 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.<ref>{{cite book |last1=Lacroix |first1=Patrick |title=John F. Kennedy and the Politics of Faith |date=2021 |publisher=University Press of Kansas |location=Lawrence |pages=93–102}}</ref><ref>{{cite book |last1=Cousins |first1=Norman |title=The Improbable Triumvirate: John F. Kennedy, Pope John, Nikita Khrushchev |date=1972 |publisher=W.W. Norton |location=New York }}</ref>

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.<ref>Stone, Oliver and Peter Kuznick, ''The Untold History of the United States'' (Gallery Books, 2012), pp. 313–314 {{ISBN?}}</ref>

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.{{sfn|Polsby|1984|p=71}} 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.<ref name=cq/> Kennedy was willing to reduce the number to six, though this was not clearly communicated to the Soviet Union.{{sfn|Evangelista|1999|p=80}} On 20 April 1963, Khrushchev withdrew support for three inspections entirely.{{sfn|Strode|1990|p=21}}

Progress was further complicated in early 1963, as a group in the [[88th United States Congress|US Congress]] called for the Soviet proposal to be discarded in favor of the Geneva System.{{sfn|Polsby|1984|p=71}} On 27 May 1963, 34 US Senators, led by Humphrey and [[Thomas J. Dodd]], introduced a [[simple resolution|resolution]] calling for Kennedy to propose another partial ban to the Soviet Union involving national monitoring and no on-site inspections. Absent Soviet agreement, the resolution called for Kennedy to continue to "pursue it with vigor, seeking the widest possible international support" while suspending all atmospheric and underwater tests. The effect of the resolution was to bolster the general push for a test ban, though Kennedy initially was concerned that it would damage attempts to secure a comprehensive ban, and had administration figures (including the Joint Chiefs of Staff) reiterate a call for a comprehensive ban.<ref name=cq/>{{sfn|Schlesinger|2002|pp=899–900}}{{sfn|Polsby|1984|p=72}} That same spring of 1963, however, Kennedy had sent antinuclear activist [[Norman Cousins]] to Moscow to meet with Khrushchev, where he explained that the political situation in the US made it very difficult for Kennedy agree to a comprehensive ban with Khrushchev's required terms. Cousins also assured Khrushchev that though Kennedy had rejected Khrushchev's offer of three yearly inspections, he still was set on achieving a test ban.{{sfn|Evangelista|1999|p=85}} In March 1963, Kennedy had also held a press conference in which he re-committed to negotiations with the Soviet Union as a means of preventing rapid nuclear proliferation, which he characterized as "the greatest possible danger and hazard."{{sfn|Rhodes|2008|p=71}}

[[File:President Kennedy American University Commencement Address June 10, 1963.jpg|thumb|[[John F. Kennedy|Kennedy]] at American University]]
One of Kennedy's advisors, [[Walt Whitman Rostow]], advised the President to make a test ban conditional on the Soviet Union withdrawing troops from [[Cuba]] and abiding by a 1962 agreement on [[Laos]], but Kennedy opted instead for test-ban negotiations without preconditions.{{sfn|Gaddis|1982|pp=228–229}} On 10 June 1963, in an effort to reinvigorate and recontextualize a test ban, President Kennedy dedicated his [[American University speech|commencement address at American University]] to "the most important topic on earth: world peace" and proceeded to make his case for the treaty.{{sfn|Schlesinger|2002|p=900}} Kennedy first called on Americans to dispel the idea that peace is unattainable. "Let us focus instead on a more practical, more attainable peace," Kennedy said, "based not on a sudden revolution in human nature but on a gradual evolution in human institutions—on a series of concrete actions and effective agreements which are in the interest of all concerned." Second, Kennedy appealed for a new attitude towards the Soviet Union, calling Americans to not "see only a distorted and desperate view of the other side, not to see conflict as inevitable, accommodations as impossible and communication as nothing more than an exchange of threats."<ref name=au/> Finally, Kennedy argued for a reduction in Cold War tensions, with a test ban serving as a first step towards complete disarmament:

<blockquote> ...&nbsp;where a fresh start is badly needed—is in a treaty to outlaw nuclear tests. The conclusion of such a treaty—so near and yet so far—would check the spiraling arms race in one of its most dangerous areas. It would place the nuclear powers in a position to deal more effectively with one of the greatest hazards which man faces in 1963, the further spread of nuclear arms. It would increase our security—it would decrease the prospects of war. Surely this goal is sufficiently important to require our steady pursuit, yielding neither to the temptation to give up the whole effort nor the temptation to give up our insistence on vital and responsible safeguards.<ref name=au>{{cite speech |title=American University's Spring Commencement 1963 |last=Kennedy |first=John F. |author-link=John F. Kennedy |date=10 June 1963 |location=[[American University]] |url=http://www1.american.edu/media/speeches/Kennedy.htm |access-date=7 August 2016 |url-status=unfit |archive-url=https://web.archive.org/web/20160816063307/http://www1.american.edu/media/speeches/Kennedy.htm |archive-date=16 August 2016}}</ref></blockquote>

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.<ref name=au/> The speech was well received by Khrushchev, who later called it "the greatest speech by any American President since [[Franklin D. Roosevelt|Roosevelt]],"{{sfn|Schlesinger|2002|p=904}} though was met with some skepticism within the US. The speech was endorsed by Humphrey and other Democrats, but labeled a "dreadful mistake" by Republican Senator [[Barry Goldwater]] and "another case of concession" by [[Everett Dirksen]], the leader of the Senate Republicans. Dirksen and [[Charles A. Halleck]], the second-ranking [[United States House of Representatives|House]] Republican, warned that the renewed negotiations might end in "virtual surrender."<ref name=cq/>

Due to prior experience in arms control and his personal relationship with Khrushchev, former [[United States Assistant Secretary of War|Assistant Secretary of War]] [[John J. McCloy]] was first considered the likely choice for chief US negotiator in Moscow, but his name was withdrawn after he turned out to be unavailable over the summer. [[W. Averell Harriman]], a former ambassador to the Soviet Union well respected in Moscow, was chosen instead.{{sfn|Schlesinger|2002|pp=902–903}} The US delegation would also include [[Adrian S. Fisher]], [[Carl Kaysen]], [[John McNaughton (government official)|John McNaughton]], and [[William R. Tyler]]. In Britain, Macmillan initially wanted David Ormsby-Gore, who had just completed a term as foreign minister, to lead his delegation, but there were concerns that Ormsby-Gore would appear to be a US "stooge" (Kennedy described him as "the brightest man he ever knew").{{sfn|Seaborg|1981|p=15}} Instead, Macmillan chose [[Quintin Hogg, Baron Hailsham of St Marylebone|Quintin Hogg]]. [[Arthur M. Schlesinger Jr.]], a special advisor to Kennedy, believed that Hogg was "ill prepared on the technicalities of the problem and was consumed by a desire to get a treaty at almost any cost."{{sfn|Schlesinger|2002|p=905}} [[Andrei Gromyko]], the Soviet [[Ministry of Foreign Affairs (Soviet Union)|Minister of Foreign Affairs]], served as Moscow's emissary.{{sfn|Schlesinger|2002|p=906}}

Heading into the negotiations, there was still no resolution within the Kennedy Administration of the question of whether to pursue a comprehensive or partial ban. In an effort to achieve the former, Britain proposed reducing the number of mandated inspections to allay Soviet concerns, but Harriman believed such a reduction would have to be paired with other concessions that Khrushchev would be able to show off within the Soviet Union and to China. Withdrawing [[PGM-19 Jupiter]] missiles from [[Italy]] and [[Turkey]] would have been an option, had they not already been removed in the wake of the Cuban Missile Crisis. In meetings prior to the negotiations, Kennedy informed Harriman that he would be willing to make concessions on the [[Berlin]] question.{{sfn|Schlesinger|2002|pp=903–904}}

On 2 July 1963, Khrushchev proposed a partial ban on tests in the atmosphere, outer space, and underwater, which would avoid the contentious issue of detecting underground tests. Notably, Khrushchev did not link this proposal to a moratorium on underground tests (as had been proposed earlier), but said it should be followed by a [[non-aggression pact]] between [[NATO]] and the [[Warsaw Pact]].{{sfn|Schlesinger|2002|p=904}} "A test ban agreement combined with the signing of a non-aggression pact between the two groups of state will create a fresh international climate more favorable for a solution of the major problems of our time, including disarmament," Khrushchev said.<ref name=khrushchevspeech>{{cite speech |title=Excerpt from Chairman Khrushchev's Speech |last=Khrushchev |first=Nikita |author-link=Nikita Khrushchev |date=2 July 1963 |location=[[East Berlin]] |url=https://books.google.com/books?id=ojBXI7fmRKIC&pg=PA1000}}</ref>

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 [[China and weapons of mass destruction#Nuclear weapons|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&nbsp;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 [[Sino-Soviet split|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.<ref name=wilsoncenter>{{cite web |title=Sharing the Bomb among Friends: The Dilemmas of Sino-Soviet Strategic Cooperation |url=https://www.wilsoncenter.org/publication/sharing-the-bomb-among-friends-the-dilemmas-sino-soviet-strategic-cooperation |publisher=[[Woodrow Wilson International Center for Scholars]] |last=Jersild |first=Austin |date=8 October 2013 |access-date=7 August 2016}}</ref> 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.{{sfn|Schlesinger|2002|p=904}} 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."{{sfn|Schlesinger|2002|p=905}}

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.{{sfn|Schlesinger|2002|pp=905–906}}

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.{{sfn|Schlesinger|2002|pp=906–907}} Ultimately, the two sides settled upon compromise language:

<blockquote>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.{{sfn|Schlesinger|2002|p=907}}</blockquote>

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 [[depositary|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.{{sfn|Schlesinger|2002|pp=907–908}} 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.{{sfn|Strode|1990|p=21}}

[[File:President Kennedy address on Test Ban Treaty, 26 July 1963.jpg|thumb|[[John F. Kennedy|Kennedy]] 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&nbsp;... 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."{{sfn|Schlesinger|2002|p=910}}<ref name=jfktv>{{cite speech |title=Address to the Nation on the Nuclear Test Ban Treaty |last=Kennedy |first=John F. |author-link=John F. Kennedy |date=26 July 1963 |url=https://www.jfklibrary.org/learn/about-jfk/historic-speeches/televised-address-on-nuclear-test-ban-treaty |access-date=7 August 2016}}</ref>

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.<ref name=cq/> For Khrushchev, the test ban negotiations had long been a means of improving the Soviet Union's global image and reducing strain in relations with the West.{{sfn|Strode|1990|p=24}} There are also some indications that military experts within the Soviet Union saw a test ban as a way to restrict US development of [[tactical nuclear weapon]]s, which could have increased US willingness to deploy small nuclear weapons on battlefields while circumventing the Soviet nuclear [[deterrence theory|deterrent]].{{sfn|Strode|1990|p=26}} Concern that a comprehensive ban would retard modernization of the Soviet arsenal may have pushed Khrushchev towards a partial ban.{{sfn|Strode|1990|p=27}} Counteracting the move towards a partial ban was Khrushchev's interest in reducing spending on testing, as underground testing was more expensive than the atmospheric tests the Soviet Union had been conducting; Khrushchev preferred a comprehensive ban as it would have eliminated the cost of testing entirely.{{sfn|Evangelista|1999|p=88}} Furthermore, there was internal concern about nuclear proliferation, particularly regarding the prospect of France and China crossing the threshold and the possibility of a multilateral NATO nuclear force, which was seen as a step towards West Germany acquiring nuclear weapons (the first Soviet test ban proposal in 1955 was made in the same month than West Germany joined NATO).{{sfn|Strode|1990|pp=28–29}}

It was not until after the agreement was reached that the negotiators broached the question of France and China joining the treaty. Harriman proposed to Khrushchev that the US lobby France while the Soviet Union pursued a Chinese signature. "That's your problem," Khrushchev said in reply.{{sfn|Schlesinger|2002|p=908}} Earlier, the Soviet ambassador to the US, Mikhail A. Menshikov, reportedly asked whether the US could "deliver the French."{{sfn|Strode|1990|p=29}} Both Kennedy and Macmillan personally called on de Gaulle to join, offering assistance to the French nuclear program in return.{{sfn|Jacobson|Stein|1966|p=465}} Nevertheless, on 29 July 1963, France announced it would not join the treaty. It was followed by China two days later.<ref name=cq/> China viewed the treaty as demonstrating a re-alignment by the United States and the Soviet Union against China, with Marshal [[Chen Yi (marshal)|Chen Yi]] characterizing the treaty as "targeted against us."<ref name="Crean">{{Cite book |last=Crean |first=Jeffrey |title=The Fear of Chinese Power: an International History |date=2024 |publisher=[[Bloomsbury Academic]] |isbn=978-1-350-23394-2 |edition= |series=New Approaches to International History series |location=London |pages=}}</ref>{{Rp|page=96}}

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.<ref name=statedept/><ref name=faschron/>

====After the Moscow agreement====
Between 8 and 27 August 1963, the [[United States Senate Committee on Foreign Relations]] held hearings on the treaty. The Kennedy administration largely presented a united front in favor of the deal. Leaders of the once-opposed Joint Chiefs of Staff (JCS) and AEC acknowledged that the treaty would be of net benefit, though Teller, former members of the JCS and AEC, and the commander of the [[Strategic Air Command]] made clear their firm opposition.{{sfn|Polsby|1984|p=72}} The opponents' argument centered on four themes. First, banning atmospheric tests would prevent the US from ensuring the [[radiation hardening|hardness]] of its [[LGM-30 Minuteman]] missile silos and, second, from developing a capable [[missile defense]] system. Third, it was argued that the Soviet Union led the US in high-yield weapons (recall the Soviet Tsar Bomba test of 1961), which required atmospheric testing banned by the treaty, while the US led the Soviet Union in low-yield weapons, which were tested underground and would be permitted by the treaty. Fourth, the ban would prevent [[peaceful nuclear explosion|peaceful, civilian uses of nuclear detonations]]. Teller declared that the treaty would be a "step away from safety and possibly&nbsp;... toward war."<ref name=cq />
[[File:President Kennedy signs Nuclear Test Ban Treaty, 07 October 1963.jpg|thumb|250px|right|[[John F. Kennedy|Kennedy]] signs the PTBT on 7 October 1963 before [[W. Averell Harriman]], [[Lyndon B. Johnson]], [[Dean Rusk]], and others]]
Administration testimony sought to counteract these arguments. Defense Secretary Robert McNamara announced his "unequivocal support" for the treaty before the Foreign Relations Committee, arguing that US nuclear forces were secure and clearly superior to those of the Soviet Union, and that any major Soviet tests would be detected. [[Glenn T. Seaborg]], the chairman of the AEC, also gave his support to the treaty in testimony, as did [[Harold Brown (Secretary of Defense)|Harold Brown]], the Department of Defense's lead scientist, and [[Norris Bradbury]], the longtime director of the Los Alamos Laboratory. [[Maxwell D. Taylor]], the [[Chairman of the Joint Chiefs of Staff]], also testified in favor of the deal. Taylor and other members of the JCS, including [[Curtis LeMay]], had made their support for the treaty conditional on four "safeguards": (1) a continued, aggressive underground testing program, (2) continued nuclear research programs, (3) continued readiness to resume atmospheric tests, and (4) improved verification equipment. Kennedy emphasized that the US would retain the ability to use nuclear weapons in war, would not be bound by the treaty if the Soviets violated it, and would continue an aggressive underground testing program. Kennedy also stressed that a ban would be a key step in preventing nuclear war.<ref name=cq />

The testimonies of the Joint Chiefs were seen as particularly effective in allaying concerns, as were the reassurances issued by Kennedy, who had acquired a reputation for resoluteness against the Soviet Union in the wake of the Cuban Missile Crisis. Additionally, a number of prominent [[Republican Party (United States)|Republicans]] came out in support of the deal, including Eisenhower, Eisenhower's vice president [[Richard Nixon]], and Senator Everett Dirksen, who had initially been skeptical of the treaty. Eisenhower's science advisor and former PSAC head, George Kistiakowsky, endorsed the treaty. Former President Harry S. Truman also lent his support. Supporters of the deal mounted a significant pressure campaign, with active lobbying in favor by a range of civilian groups, including the [[United Automobile Workers]]/[[AFL–CIO]], the [[Peace Action|National Committee for a Sane Nuclear Policy]], [[Women Strike for Peace]], and [[Methodism|Methodist]], [[Unitarian Universalism|Unitarian Universalist]], and [[Reform Judaism|Reform Jewish]] organizations. Jerome Wiesner, the chairman of PSAC, later said that this public advocacy was a primary motivation for Kennedy's push for a test ban.{{sfn|Evangelista|1999|p=88}} Civil opposition to the deal was less prominent, though the [[Veterans of Foreign Wars]] announced opposition to the deal along with the [[International Council of Christian Churches]], which rejected a "covenant with a [[religion in the Soviet Union|godless power]]." Polling in late August 1963 indicated that more than 60% of Americans supported the deal while less than 20% opposed it.<ref name=cq />{{sfn|Terchek|1970|pp=135–136}}

On 3 September 1963, the Foreign Relations Committee approved the treaty by a 16–1 vote. On 24 September 1963, the US Senate voted 80–14 to approve ratification of the treaty, exceeding the necessary two-thirds majority by 14 votes. The Soviet Union ratified the treaty the following day with a unanimous vote of the [[Presidium of the Supreme Soviet]].{{sfn|Jacobson|Stein|1966|p=464}} On 10 October 1963, the treaty entered into effect.<ref name=cq /><ref name=armcontrol.org>{{cite web |title=Nuclear Testing and Comprehensive Test Ban Treaty (CTBT) Timeline |publisher=[[Arms Control Association]] |last1=Kimball |first1=Daryl G. |last2=Taheran |first2=Shervin |url=https://www.armscontrol.org/factsheets/Nuclear-Testing-and-Comprehensive-Test-Ban-Treaty-CTBT-Timeline |date=22 September 2015 |access-date=11 August 2016 |archive-date=21 April 2020 |archive-url=https://web.archive.org/web/20200421174531/https://www.armscontrol.org/factsheets/Nuclear-Testing-and-Comprehensive-Test-Ban-Treaty-CTBT-Timeline |url-status=dead }}</ref><ref name=unoda />