Editing Partial Nuclear Test Ban Treaty (section)

==Background==
[[File:Bravo fallout2.png|thumb|300px|Castle Bravo fallout plume]]
The primary motivation for 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.<ref name=atomicheritage/> In 1952–53, both the United States and the Soviet Union detonated their first [[thermonuclear weapons]] (hydrogen bombs), which were significantly more powerful than the [[atomic bombs]] that had been tested and deployed since the [[Trinity test]] in 1945.<ref name="statedept">{{cite web |title=Limited Test Ban Treaty |url=https://2009-2017.state.gov/t/isn/4797.htm |publisher=US Department of State |access-date=31 July 2016}}</ref><ref name=atomicvshydrogen>{{cite news |title=A-bombs vs. H-bombs: What's the difference? |work=[[The Globe and Mail]] |date=28 March 2016 |agency=[[Associated Press]] |url=https://www.theglobeandmail.com/news/world/a-bombs-vs-h-bombs-whats-thedifference/article28030528/ |last=Kageyama |first=Yuri |access-date=31 July 2016}}</ref> 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 the worst radiological event in US history as radioactive particles spread over more than {{convert|11,000|km2|mi2|sp=us}}, affected inhabited areas (including [[Rongelap Atoll]] and [[Utirik Atoll]]), and sickened Japanese fishermen aboard the ''[[Daigo Fukuryū Maru|Lucky Dragon]]'' upon whom "ashes of death" had rained.<ref name=atomicheritage>{{cite web |title=Limited or Partial Test Ban Treaty (LTBT/PTBT) |publisher=[[Atomic Heritage Foundation]] |url=https://www.atomicheritage.org/history/limited-or-partial-test-ban-treaty-ltbtptbt |access-date=1 August 2016}}</ref><ref name=bravo>{{cite web |title=1 March 1954 – Castle Bravo |publisher=[[Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization]] |url=https://www.ctbto.org/specials/testing-times/1-march-1954-castle-bravo/ |access-date=31 July 2016}}</ref>{{sfn|Schlesinger|2002|p=450}}{{sfn|Rhodes|2005|p=542}} In the same year, a Soviet test sent radioactive particles over Japan.{{sfn|Burns|Siracusa|2013|p=247}} Around the same time, victims of the [[atomic bombings of Hiroshima and Nagasaki|atomic bombing of Hiroshima]] visited the US for medical care, which attracted significant public attention.<ref name=nsarchive>{{cite web |title=The Making of the Limited Test Ban Treaty, 1958–1963 |last1=Burr |first1=William |last2=Montford |first2=Hector L. |publisher=[[National Security Archive]] |date=3 August 2003 |url=https://nsarchive2.gwu.edu/NSAEBB/NSAEBB94/ |access-date=7 August 2016}}</ref> In 1961, the Soviet Union tested the [[Tsar Bomba]], which had a yield of 50 megatons and remains the most powerful human-made explosion in history, though due to use of a [[lead]] [[Tamper (nuclear weapon)|tamper]], fallout was relatively limited.<ref name=tsar>{{cite web |title=30 October 1961 – The Tsar Bomba |publisher=Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization |url=https://www.ctbto.org/specials/testing-times/30-october-1961-the-tsar-bomba/ |access-date=31 July 2016}}</ref><ref name=tsar2>{{cite journal |title=Tsar Bomba: The World's Most Powerful Nuclear Weapon |journal=Slate |last=Morton |first=Ella |url=http://www.slate.com/blogs/atlas_obscura/2014/10/30/tsar_bomba_the_most_powerful_nuclear_weapon_ever.html |date=30 October 2014 |access-date=31 July 2016}}</ref><ref name=bulletin>{{cite journal |title=The Khariton Version |last1=Khariton |first1=Yulii |author-link1=Yulii Khariton |last2=Smirnov |first2=Yuri |journal=[[Bulletin of the Atomic Scientists]] |volume=49 |pages=20–31 |number=4 |date=May 1993|doi=10.1080/00963402.1993.11456341 |url=http://www.thebulletin.org/issues/1993/may93/may93Khariton.html |access-date=3 August 2016 |url-status=unfit |archive-url=https://web.archive.org/web/20030221213340/http://www.thebulletin.org/issues/1993/may93/may93Khariton.html |archive-date=21 February 2003|bibcode=1993BuAtS..49d..20K }}</ref> 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 the US).<ref name=nrdc>{{cite web |title=Archive of Nuclear Data |url=http://www.nrdc.org/nuclear/nudb/datab15.asp |publisher=[[Natural Resources Defense Council]] |access-date=6 August 2016 |url-status=unfit |archive-url=https://web.archive.org/web/20071010072829/http://www.nrdc.org/nuclear/nudb/datab15.asp |archive-date=10 October 2007}}</ref>