Editing Weapon of mass destruction (section)

===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}}