Editing Weapon of mass destruction (section)

==Use, possession, and access==

===Nuclear weapons===
{{Main|Nuclear warfare|List of states with nuclear weapons}}
[[File:US and USSR nuclear stockpiles.svg|thumb|250x250px|US and Soviet/Russian nuclear stockpiles, 1945 to 2014]]
Nuclear weapons use the energy inside of an atom's nucleus to create massive explosions. This goal is achieved through nuclear fission and fusion.<ref name=":4">{{Cite web |title=How Nuclear Weapons Work {{!}} Union of Concerned Scientists |url=https://www.ucsusa.org/resources/how-nuclear-weapons-work |access-date=2024-05-16 |website=www.ucsusa.org |language=en}}</ref>

Nuclear fission is when the nucleus of an atom is split into smaller nuclei. This process can be induced by shooting a neutron at the nucleus of an atom. When the neutron is absorbed by the atom, it becomes unstable, causing it to split and release energy.<ref name=":4" /> Modern nuclear weapons start this process by detonating chemical explosives around a pit of either uranium-235 or plutonium-239 metal.<ref name=":4" /> The force from this detonation is directed inwards, causing the pit of uranium or plutonium to compress to a dense point. Once the uranium/plutonium is dense enough, neutrons are then injected. This starts a fission chain reaction also known as an atomic explosion.<ref name=":4" />

Nuclear fusion is essentially the opposite of fission. It is the fusing together of nuclei, not the splitting of it. When exposed to extreme pressure and temperature, some lightweight nuclei can fuse together and form heavier nuclei, releasing energy in the process.<ref name=":4" /> Fusion weapons (also known as “thermonuclear” or “hydrogen” weapons) use the fission process to initiate fusion. Fusion weapons use the energy released from a fission explosion to fuse hydrogen isotopes together.<ref name=":4" /> The energy released from these weapons creates a fireball, which reaches tens of million degrees. A temperature of this magnitude is similar to the temperature found at center of the sun; the sun runs on fusion as well.<ref name=":4" />

The only country to have used a nuclear weapon in war is the [[The United States and weapons of mass destruction|United States]], which [[Atomic bombings of Hiroshima and Nagasaki|dropped two atomic bombs]] on the Japanese cities of [[Hiroshima]] and [[Nagasaki]] during World War II.

At the start of 2024, nine states—the United States, Russia, the United Kingdom, France, China, India, Pakistan, the Democratic People’s Republic of Korea (North Korea) and Israel—together possessed approximately 12 121 nuclear weapons, of which 9585 were considered to be potentially operationally available. An estimated 3904 of these warheads were deployed with operational forces, including about 2100 that were kept in a state of high operational alert—about 100 more than the previous year.<ref>{{cite book |chapter= World nuclear forces |title=SIPRI Yearbook 2024 |date=2024|last1=Kristensen |first1=Hans M. |last2=Korda |first2=Matt |last3= Friess | first3= Friederike | last4= Mian |first4=Zia | last5=Podvig | first5=Pavel| ISBN= 9780198930570}}</ref>

<!-- Deleted image removed: [[File:Global nuclear weapon inventories, January 2024.png|thumb|Global nuclear weapon inventories, January 2024|alt=File:Global nuclear weapon inventories, January 2024.png]] -->
[[South Africa and weapons of mass destruction|South Africa]] developed a small nuclear arsenal in the 1980s but disassembled them in the early 1990s, making it the only country to have fully given up an independently developed nuclear weapons arsenal. [[Belarus]], [[Kazakhstan]], and [[Ukraine]] inherited stockpiles of nuclear arms following the break-up of the [[Soviet Union]], but relinquished them to the Russian Federation.<ref>{{cite book |doi=10.1016/B978-0-12-803678-5.00491-4 |chapter=Weapons of Mass Destruction |title=International Encyclopedia of Public Health |date=2017 |last1=Sidel |first1=Victor W. |last2=Levy |first2=Barry S. |pages=402–407 |isbn=978-0-12-803708-9 }}</ref>

Countries where nuclear weapons are deployed through [[nuclear sharing]] agreements include Belgium, [[Germany and weapons of mass destruction|Germany]], Italy, the [[Netherlands and weapons of mass destruction|Netherlands]], and [[Turkey]].<ref>{{Cite web|url=https://www.nti.org/analysis/articles/nato-nuclear-disarmament/|title=U.S. Nuclear Weapons in Europe {{!}} NATO Nuclear Weapons Policy {{!}} NTI|website=nti.org|access-date=2019-03-19|archive-url=https://web.archive.org/web/20181107233042/https://www.nti.org/analysis/articles/nato-nuclear-disarmament/|archive-date=7 November 2018|url-status=live}}</ref>

=== Biological weapons ===
{{Main|Biological warfare|Biological weapons}}[[File:Biological Weapons Convention original document.png|thumb|The Biological Weapons Convention<ref>United Nations (1972). [https://front.un-arm.org/wp-content/uploads/2020/12/BWC-text-English.pdf Biological Weapons Convention].
</ref>]]The [[history of biological warfare]] goes back at least to the [[Golden Horde|Mongol]] [[siege of Caffa]] in 1346 and possibly much farther back to antiquity.<ref>{{Cite journal|last=Wheelis|first=Mark|date=September 2002|title=Biological Warfare at the 1346 Siege of Caffa|journal= Emerging Infectious Diseases|language=en-us|volume=8|issue=9|pages=971–975|doi=10.3201/eid0809.010536|pmid=12194776|pmc=2732530|doi-access=free}}</ref> It is believed that the [[Ancient Greece|Ancient Greeks]] contaminated their adversaries' wells by placing animal corpses in them.<ref>{{Cite book|last=Mayor|first=Adrienne|title=Greek Fire, Poison Arrows & Scorpion Bombs: Biological and Chemical Warfare in the Ancient World|publisher=Abrams Press|year=2003|isbn=978-1585673483}}</ref><ref name=":0">{{Cite news |title=The A to Z of international relations |language=en |newspaper=The Economist |url=https://www.economist.com/international-relations-a-to-z |access-date=2023-11-23}}</ref> However, only by the turn of the 20th century did advances in [[microbiology]] allow for the large-scale weaponization of pathogens. During [[World War I|First World War]], German military attempted to introduce anthrax into Allied livestock. In [[World War II|Second World War]], Japan conducted aerial attacks on China using fleas carrying the bubonic plague.<ref name=":0" /> During the 20th century, at least nine states have operated offensive biological weapons programs, including [[Canada and weapons of mass destruction|Canada]] (1946–1956),<ref>{{Cite web|title=Canada|url=https://www.nti.org/learn/countries/canada/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> [[France and weapons of mass destruction|France]] (1921–1972),<ref>{{Cite web|title=France|url=https://www.nti.org/learn/countries/france/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> [[Iraqi biological weapons program|Iraq]] (1985–1990s),<ref>{{Cite web|title=Iraq|url=https://www.nti.org/learn/countries/iraq/biological/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> [[Japan and weapons of mass destruction|Japan]] (1930s–1945),<ref>{{Cite web|title=Japan|url=https://www.nti.org/learn/countries/japan/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> [[Rhodesia and weapons of mass destruction|Rhodesia]], [[South Africa and weapons of mass destruction|South Africa]] (1981–1993),<ref>{{Cite web|title=South Africa|url=https://www.nti.org/learn/countries/south-africa/biological/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> the [[Soviet biological weapons program|Soviet Union]] (1920s–1992),<ref>{{Cite web|title=Russia|url=https://www.nti.org/learn/countries/russia/biological/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> the [[United Kingdom and weapons of mass destruction|United Kingdom]] (1934–1956),<ref>{{Cite web|title=United Kingdom|url=https://www.nti.org/learn/countries/united-kingdom/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> and the [[United States biological weapons program|United States]] (1943–1969).<ref>{{Cite web|title=United States|url=https://www.nti.org/learn/countries/united-states/biological/|access-date=2021-03-04|website=[[Nuclear Threat Initiative]]}}</ref> The Japanese biological weapons program, which was run by the secret [[Imperial Japanese Army]] [[Unit 731]] during the Sino-Japanese War (1937–1945), became infamous for conducting often fatal [[Human experimentation|human experiments]] on prisoners and producing biological weapons for combat use.<ref>{{Cite book|last=Dando|first=Malcolm|title=Chapter 2: Biological warfare before 1945. In Bioterror and Biowarfare: A Beginner's Guide|publisher=Oneworld|year=2006|isbn=9781851684472|pages=11–31}}</ref> The [[Soviet Union]] covertly operated the world's largest, longest, and most sophisticated biological weapons program, in violation of its obligations under international law.<ref>{{cite book |chapter=Conclusion |pages=698–712 |jstor=j.ctt2jbscf.30 |last1=Leitenberg |first1=Milton |last2=Zilinskas |first2=Raymond A. |last3=Kuhn |first3=Jens H. |title=The Soviet Biological Weapons Program: A History |date=2012 |publisher=Harvard University Press |isbn=978-0-674-04770-9 }}</ref>

International restrictions on biological warfare began with the 1925 [[Geneva Protocol]], which prohibits the use but not the possession or development of biological and chemical weapons.<ref name=":3">{{cite journal |last1=Baxter |first1=R. R. |last2=Buergenthal |first2=Thomas |title=Legal Aspects of the Geneva Protocol of 1925 |journal=American Journal of International Law |date=October 1970 |volume=64 |issue=5 |pages=853–879 |doi=10.2307/2198921 |jstor=2198921 }}</ref><ref>{{Cite web|title=Text of the 1925 Geneva Protocol|url=http://disarmament.un.org/treaties/t/1925/text|url-status=dead|access-date=2021-03-02|website=[[United Nations Office for Disarmament Affairs]]|archive-date=9 February 2021|archive-url=https://web.archive.org/web/20210209134308/http://disarmament.un.org/treaties/t/1925/text}}</ref> Upon ratification of the Geneva Protocol, several countries made [[Reservation (law)|reservations]] regarding its applicability and use in retaliation.<ref>{{Cite web|title=Disarmament Treaties Database: 1925 Geneva Protocol|url=http://disarmament.un.org/treaties/t/1925|url-status=dead|access-date=2021-03-02|website=[[United Nations Office for Disarmament Affairs]]|archive-date=21 May 2019|archive-url=https://web.archive.org/web/20190521142454/http://disarmament.un.org/treaties/t/1925}}</ref> Due to these reservations, it was in practice a "[[No first use|no-first-use]]" agreement only.<ref>{{cite journal |last1=Beard |first1=Jack M. |title=The Shortcomings of Indeterminacy in Arms Control Regimes: The Case of the Biological Weapons Convention |journal=American Journal of International Law |date=April 2007 |volume=101 |issue=2 |pages=271–321 |doi=10.1017/S0002930000030098 }}</ref> The 1972 [[Biological Weapons Convention]] (BWC) supplements the Geneva Protocol by prohibiting the development, production, acquisition, transfer, stockpiling, and use of biological weapons.<ref name=":2">{{Cite web|title=Biological Weapons Convention|url=https://www.un.org/disarmament/biological-weapons/|url-status=live|archive-url=https://web.archive.org/web/20210215200800/https://www.un.org/disarmament/biological-weapons|archive-date=2021-02-15|access-date=2021-03-02|website=[[United Nations Office for Disarmament Affairs]]|language=en-US}}</ref> Having entered into force on 26 March 1975, the BWC was the first multilateral disarmament treaty to ban the production of an entire category of weapons of mass destruction.<ref name=":2" /> As of March 2021, [[List of parties to the Biological Weapons Convention|183 states have become party to the treaty]].<ref name=":1">{{Cite web|title=Disarmament Treaties Database: Biological Weapons Convention|url=http://disarmament.un.org/treaties/t/bwc|url-status=dead|access-date=2021-03-02|website=[[United Nations Office for Disarmament Affairs]]|archive-date=2 February 2021|archive-url=https://web.archive.org/web/20210202055505/http://disarmament.un.org/treaties/t/bwc}}</ref>

===Chemical weapons===
{{main|Chemical warfare}}
Chemical weapons have been used around the world by various civilizations since ancient times. The oldest reported case of a chemical substance being used as a weapon was in 256 AD <!-- Source Vilches, Diego (Nov 15 2015) mistakenly writes 256 BC, however all other sources agree on 256 AD, see article on [[Dura-Europos]] for more detail -->  during the siege of [[Dura-Europos]]. A mixture of tar and sulfur was used to produce sulfur oxides, which helped take control of the city.<ref>{{Cite journal |last=Vilches |first=Diego |date=November 15, 2015 |title=One hundred and one years after a milestone: Modern chemical weapons and World War I |url=https://revistas.unam.mx/index.php/req/article/view/63852 |journal=Educacion Quimica (Chemistry Education) |volume=27 |issue=3}}</ref><ref>{{cite web |title=Gas Warfare at Dura-Europos |url=http://www.archaeology.co.uk/cwa/world-news/death-underground-gas-warfare-at-dura-europos.htm |website=World Archaeology |access-date=22 December 2021 |date=7 November 2009}}</ref> In the industrial era, chemical weapons were used extensively by both sides during [[Chemical weapons in World War I|World War I]], and by the Axis powers during [[World War II]] (both in battle and in extermination camp [[Gas chamber#Germany|gas chambers]]) though Allied powers also stockpiled them. 

International restrictions on chemical warfare began with the [[Hague Conventions of 1899 and 1907]], and was expanded significantly by the 1925 [[Geneva Protocol]]. These treaties prohibited the use of poisons or chemical agents in international warfare, but did not place restrictions on development or weapon stockpiles. Since 1997, the [[Chemical Weapons Convention|Chemical Weapons Convention (CWC)]] has expanded restrictions to prohibit any use and development of chemical weapons except for very limited purposes (research, medical, pharmaceutical or protective). As of 2018, a handful of countries have known inventories, and many are in the process of being safely destroyed.<ref name=":22">{{cite journal |last1=Timperley |first1=Christopher M. |last2=Forman |first2=Jonathan E. |last3=Abdollahi |first3=Mohammad |last4=Al-Amri |first4=Abdullah Saeed |last5=Alonso |first5=Isel Pascual |last6=Baulig |first6=Augustin |last7=Borrett |first7=Veronica |last8=Cariño |first8=Flerida A. |last9=Curty |first9=Christophe |last10=Berrutti |first10=David González |last11=Kovarik |first11=Zrinka |last12=Martínez-Álvarez |first12=Roberto |last13=Mikulak |first13=Robert |last14=Mourão |first14=Nicia Maria Fusaro |last15=Ponnadurai |first15=Ramasami |last16=Neffe |first16=Slawomir |last17=Raza |first17=Syed K. |last18=Rubaylo |first18=Valentin |last19=Takeuchi |first19=Koji |last20=Tang |first20=Cheng |last21=Trifirò |first21=Ferruccio |last22=van Straten |first22=Francois Mauritz |last23=Vanninen |first23=Paula S. |last24=Zaitsev |first24=Volodymyr |last25=Waqar |first25=Farhat |last26=Zina |first26=Mongia Saïd |last27=Blum |first27=Marc-Michael |last28=Gregg |first28=Hugh |last29=Fischer |first29=Elena |last30=Sun |first30=Siqing |last31=Yang |first31=Pei |title=Advice on chemical weapons sample stability and storage provided by the Scientific Advisory Board of the Organisation for the Prohibition of Chemical Weapons to increase investigative capabilities worldwide |journal=Talanta |date=October 2018 |volume=188 |pages=808–832 |doi=10.1016/j.talanta.2018.04.022 |pmid=30029449 }}</ref> Nonetheless, proliferation and use in war zones remains an active concern, most recently the [[use of chemical weapons in the Syrian Civil War]].

{{CW Proliferation}}