Editing Manhattan Project (section)

== Secrecy ==
[[File:Oak Ridge Wise Monkeys.jpg|thumb|A billboard encouraging secrecy among Oak Ridge workers|alt=Uncle Sam has removed his hat and is rolling up his sleeves. On the wall in front of him are three monkeys and the slogan: What you see here/ What you do here/ What you hear here/ When you leave here/ Let it stay here.]]

The Manhattan Project operated under a mandate of "absolute secrecy" from Roosevelt, meaning that the very existence of the project itself was to be kept secret. This proved a daunting task given the amount of knowledge and speculation about nuclear fission that existed prior to the Manhattan Project, the huge numbers of people involved, and the scale of the facilities.<ref name="wellerstein_med_secrecy">{{harvnb|Wellerstein|2021|pp=43, 52–96}}</ref> Groves adopted an extreme version of [[Compartmentalization (information security)|compartmentalization]] (the [[need-to-know]] policy):

{{blockquote|Compartmentalization of knowledge, to me, was the very heart of security. My rule was simple and not capable of misinterpretation—each man should know everything he needed to know to do his job and nothing else. Adherence to this rule not only provided an adequate measure of security, but it greatly improved over-all efficiency by making our people stick to their knitting. And it made quite clear to all concerned that the project existed to produce a specific end product—not to enable individuals to satisfy their curiosity and to increase their scientific knowledge.<ref>{{harvnb|Groves|1962|p=140}}.</ref>}}

This clashed with the norms of many of the scientists involved, who claimed that science could not operate successfully under such requirements. The Manhattan Project officials also had difficulty with journalists, Congressmen, federal officials who were not "in the know", residents near local sites, judges adjudicating land claims, and other sources of speculation, prying, and leaks, along with concerns about [[espionage]] and [[sabotage]]. Groves relied on the [[FBI]] and his own autonomous [[G-2 (intelligence)|G-2 intelligence unit]] to investigate potential security violations. Ultimately over 1,500 "loose talk" cases were investigated during the war.<ref name="wellerstein_med_secrecy"/>

Because of its relative success at keeping the story out of newspapers, [[Byron Price]], head of the [[Office of Censorship]], ultimately designated the Manhattan Project "the best-kept secret of the war".{{r|ap19450808}} In 1945 ''[[Life (magazine)|Life]]'' estimated that before the Hiroshima and Nagasaki bombings "probably no more than a few dozen men in the entire country knew the full meaning of the Manhattan Project, and perhaps only a thousand others even were aware that work on atoms was involved." The magazine wrote that the more than 100,000 others employed with the project "worked like moles in the dark". Warned that disclosing the project's secrets was punishable by 10 years in prison or a fine of {{US$|10000|1945|round=-3}}, they monitored "dials and switches while behind thick concrete walls mysterious reactions took place" without knowing the purpose of their jobs.<ref name="life1945082091">{{cite news |url=https://books.google.com/books?id=hkgEAAAAMBAJ&pg=PA91 |title=Manhattan Project: Its Scientists Have Harnessed Nature's Basic Force |newspaper=Life |date=20 August 1945 |access-date=25 November 2011 |last=Wickware |first=Francis Sill |pp=2, 91}}</ref><ref name="owens">{{cite magazine |url=https://www.theatlantic.com/infocus/2012/06/the-secret-city/100326/#img06 |title=The Secret City/ Calutron operators at their panels, in the Y-12 plant at Oak Ridge, Tennessee, during World War II. |magazine=The Atlantic |date=25 June 2012 |access-date=25 June 2012}}</ref><ref name="wellerstein20120416">{{cite web |url=http://blog.nuclearsecrecy.com/2012/04/16/oak-ridge-confidential-or-baseball-for-bombs/ |title=Oak Ridge Confidential, or Baseball for Bombs |publisher=Restricted Data |date=16 April 2012 |access-date=7 April 2013 |last=Wellerstein |first=Alex |archive-url=https://web.archive.org/web/20130117023813/http://nuclearsecrecy.com/blog/2012/04/16/oak-ridge-confidential-or-baseball-for-bombs/ |archive-date=17 January 2013 |url-status=live}}</ref>

In December 1945 the US Army published a secret report assessing the security apparatus surrounding the Manhattan Project. The report states that the project was "more drastically guarded than any other highly secret war development." The surrounding security infrastructure was so vast and thorough that in the early days of the project in 1943, investigators vetted 400,000 potential employees and 600 companies for potential security risks.<ref>{{Cite news|last=Roberts|first=Sam|date=29 September 2014|title=The Difficulties of Nuclear Containment|newspaper=The New York Times|url=https://www.nytimes.com/2014/09/30/science/espionage-threatened-the-manhattan-project-declassified-report-says.html|access-date=6 May 2020|issn=0362-4331}}</ref>

=== Censorship ===
[[File:Are your drawers closed? Manhattan Project security poster.png|thumb|Security poster, warning office workers to close drawers and put documents in safes when not being used]]
Voluntary censorship of atomic information began before the Manhattan Project. After the start of the European war in 1939 American scientists began avoiding publishing military-related research, and in 1940 scientific journals began asking the [[National Academy of Sciences]] to clear articles. [[William L. Laurence]] of ''[[The New York Times]]'', who wrote an article on atomic fission in ''[[The Saturday Evening Post]]'' of 7 September 1940, later learned that government officials asked librarians nationwide in 1943 to withdraw the issue.<ref>{{harvnb|Sweeney|2001|pp=196–198}}.</ref> The Soviets noticed the silence, however. In April 1942 nuclear physicist [[Georgy Flyorov]] wrote to [[Joseph Stalin]] on the absence of articles on nuclear fission in American journals; this resulted in the [[Soviet Union]] establishing its own atomic bomb project.<ref>{{harvnb|Holloway|1994|pp=76–79}}.</ref>

The Manhattan Project operated under tight security lest its discovery induce Axis powers, especially Germany, to accelerate their own nuclear projects or undertake covert operations against the project.<ref>{{harvnb|Jones|1985|pp=253–255}}.</ref> The Office of Censorship relied on the press to comply with a voluntary code of conduct it published, and the project at first avoided notifying the office. By early 1943 newspapers began publishing reports of large construction in Tennessee and Washington, and the office began discussing with the project how to maintain secrecy. In June it asked newspapers and broadcasters to avoid discussing "atom smashing, atomic energy, atomic fission, atomic splitting, or any of their equivalents. The use for military purposes of radium or radioactive materials, heavy water, high voltage discharge equipment, cyclotrons."<ref>{{harvnb|Sweeney|2001|pp=198–200}}.</ref><ref name="ap19450808">{{cite news |url=https://news.google.com/newspapers?id=8CZdAAAAIBAJ&sjid=0loNAAAAIBAJ&pg=1159%2C1605869 |title=No News Leaked Out About Bomb |newspaper=Lawrence Journal-World |date=8 August 1945 |agency=Associated Press |access-date=15 April 2012 |page=5}}</ref>

=== Soviet spies ===
{{Main|Atomic spies}}
The prospect of sabotage was always present, and sometimes suspected when there were equipment failures. While there were some problems believed to be the result of careless or disgruntled employees, there were no confirmed instances of Axis-instigated sabotage.<ref>{{harvnb|Jones|1985|pp=263–264}}.</ref> However, on 10 March 1945, a Japanese [[fire balloon]] struck a power line, and the resulting power surge caused the three reactors at Hanford to be temporarily shut down.<ref>{{harvnb|Jones|1985|p=267}}.</ref> With so many people involved, security was difficult. A special [[Counter Intelligence Corps]] detachment was formed to handle the project's security issues.<ref>{{harvnb|Jones|1985|pp=258–260}}.</ref> By 1943, it was clear that the Soviet Union was attempting to penetrate the project. Lieutenant Colonel [[Boris T. Pash]], the head of the Counter Intelligence Branch of the [[Western Defense Command]], investigated suspected Soviet espionage at the Radiation Laboratory in Berkeley. Oppenheimer informed Pash that he had been approached by a fellow professor at Berkeley, [[Haakon Chevalier]], about passing information to the Soviet Union.<ref>{{harvnb|Jones|1985|pp=261–265}}.</ref>

The most successful Soviet spy was [[Klaus Fuchs]], a physicist and member of the British Mission who was intimately involved in work at Los Alamos on the design of the implosion bomb.<ref>{{harvnb|Groves|1962|pp=142–145}}.</ref> His espionage activities were not identified until 1950, as a result of [[Venona project]]. The revelation of his espionage activities damaged the United States' nuclear cooperation with Britain and Canada,<ref>{{harvnb|Hewlett|Duncan|1969|pp=312–314}}.</ref> and other instances of espionage were subsequently uncovered, leading to the arrest of [[Harry Gold]], [[David Greenglass]], and [[Julius and Ethel Rosenberg]].<ref>{{harvnb|Hewlett|Duncan|1969|p=472}}.</ref> Other spies like [[George Koval]] and [[Theodore Hall]] remained unknown for decades.<ref>{{cite news |last=Broad |first=William J.|date=12 November 2007|url=https://www.nytimes.com/2007/11/12/us/12koval.html |title=A Spy's Path: Iowa to A-Bomb to Kremlin Honor|newspaper=[[The New York Times]]|pages=1–2|access-date=2 July 2011}}</ref> The value of the espionage is difficult to quantify, as the principal constraint on the [[Soviet atomic bomb project]] was their short supply of uranium ore. It may have saved the Soviets at least one or two years in the development of their own bomb,<ref>{{harvnb|Holloway|1994|pp=222–223}}.</ref> although some historians have argued the Soviets spent as much time vetting and reduplicating the information as they would have saved had they trusted it.<ref>{{cite book|last=Gordin|first=Michael D.|title=Red Cloud at Dawn: Truman, Stalin, and the End of the Atomic Monopoly|publisher=Farrar, Straus, and Giroux|year=2009|pages=153–156}}</ref>