The Kremlin has denied any intention to use chemical weapons. But the Russian government has been linked over the past two decades with this type of attack. And concern over President Vladimir Putin\u2019s intentions spiked on 28 March,\u00a0when\u00a0The<\/i>\u00a0Wall Street Journal<\/i>\u00a0reported<\/a>\u00a0that envoys and mediators in Russia\u2013Ukraine peace talks earlier in the month had been poisoned \u2014 although at least one Ukrainian government source\u00a0has reportedly denied the story<\/a>.<\/p>\n Nature<\/i>\u00a0spoke to several analysts to explore the chances of chemical weapons being deployed in the war.<\/p>\n Why do Western leaders think Russia might use chemical weapons in Ukraine?<\/strong><\/p>\n Even though the world has outlawed the use of chemical weapons, the Russian government has been linked to them on several occasions, some recent.<\/p>\n In 2018,\u00a0the UK government accused Russia<\/a>\u00a0of using a Novichok chemical \u2014 a nerve agent developed by the Soviet Union decades ago \u2014 to poison Sergei Skripal, a Russian former double agent living in the United Kingdom. In another high-profile incident,\u00a0Russian opposition leader Alexei Navalny was poisoned<\/a>\u00a0with a different type of Novichok agent in 2020. The Kremlin denied involvement in either event.<\/p>\n \u201cThese two incidents raise question marks on whether elements of the former Soviet programme have not been eliminated,\u201d says Ralf Trapp, a disarmament consultant based in Chessenaz, France.<\/p>\n Furthermore, Russian troops have fought alongside the regular Syrian army during that country\u2019s civil war, which began in 2011. The Organisation for the Prohibition of Chemical Weapons (OPCW), based in The Hague, the Netherlands, confirmed that\u00a0the Syrian army deployed chemical weapons<\/a>\u00a0against its own people. The Russian government denied involvement in any of these attacks.<\/p>\n When it comes to Ukraine, the Russian government has accused the country of preparing to use chemical weapons. But Western governments say this could be a \u2018false flag\u2019 tactic, which the Kremlin has used in the past. \u201cRussia has a long track record of accusing others of what they are either already doing or about to do,\u201d said US President Joe Biden on 22 March,\u00a0according to news outlet CNBC<\/a>.<\/p>\n Trapp, who is a former OPCW officer and was involved in verifying adherence to the 1997 Chemical Weapons Convention (CWC) in several countries, including Ukraine, says there is no evidence that Ukraine has chemical weapons. \u201cIt doesn\u2019t make any sense for the Ukrainians to think of using them,\u201d he adds.<\/p>\n Russia and Ukraine are signatories to the CWC, which outlaws the use of chemicals in warfare. This includes substances with legitimate applications such as chlorine, which is used, for instance, to sanitize water. The OPCW, which monitors compliance to the treaty,\u00a0verified in 2017<\/a>\u00a0that Russia had destroyed all its declared stockpiles of chemical weapons.<\/p>\n If Russia or any other signatory uses chemical weapons, it\u2019s a breach of the convention, says Leiv Sydnes, a chemist at the University of Bergen in Norway, who has chaired a task group for the OPCW and helped to draft previous reviews of the treaty.<\/p>\n The\u00a0Russian Foreign Ministry has called accusations<\/a>\u00a0that the country\u2019s military plans to use chemical weapons in Ukraine a \u201csmear campaign\u201d by Western nations.<\/p>\n Why would Russia use chemical weapons in Ukraine?<\/strong><\/p>\n Analysts say that chemical weapons have limited usefulness in the battleground, especially against armies, such as Ukraine\u2019s, that are equipped with protective gear. \u201cIf you are using them against a military target, it is relatively straightforward for the defenders to have CBW [chemical- and biological-weapon] protection kits,\u201d says Paul Rogers, a peace-studies researcher at the University of Bradford, UK.<\/p>\n Instead, chemical weapons are primarily a tool for terrorizing populations and breaking their will to resist, Rogers and other researchers say. \u201cThe main purpose to use chemical weapons is to terrify people and to generate panic,\u201d Sydnes says.<\/p>\n Observers fear that the Russian military could launch chemical attacks on Ukrainian cities to cause panic amongst civilians. Chlorine gas, in particular, is denser than air and could settle into the underground shelters used by the populations of cities during bombardments, causing people to suffocate.<\/p>\n The Russian military could also use nerve agents such as sarin, which is extremely deadly but dissipates quickly, enabling the attacking army to subsequently occupy the targeted site. Chemicals such as Novichok agents, though, would be less practical for Russian troops because these substances are persistent and would require extensive decontamination before the army could occupy the site.<\/p>\n Recent developments on the ground, with the Russian military seemingly refocusing its efforts on eastern regions of Ukraine, could make a chemical attack less likely, Rogers says. \u201cI think the risk is less than two or three weeks ago.\u201d<\/p>\n Is there any way to prevent the use of chemical weapons in Ukraine?<\/strong><\/p>\n If the Kremlin is serious about its accusation that Ukraine is preparing to use chemical weapons, it could pursue its allegations through the proper channels. \u201cThey can demand from the OPCW what is called a challenge inspection,\u201d Sydnes says. \u201cIf this is a real issue for Putin, and he doesn\u2019t want to use chemical weapons, that is what he should do.\u201d<\/p>\n But if the Russian government is claiming that Ukraine has chemical weapons as a pretext to use such weapons itself, then any country \u2014 even Ukraine \u2014 could trigger OPCW inspections of Ukraine to challenge the assertion. \u201cThe Ukrainians could say, \u2018Come and have a look, we have nothing to hide\u2019,\u201d says Alastair Hay, an environmental toxicologist at the University of Leeds, UK. \u201cThat would clearly wrong-foot the Russians.\u201d<\/p>\n In either scenario, international inspectors would need guarantees for their safety, such as a ceasefire in the areas they are visiting.<\/p>\n The OPCW told\u00a0Nature<\/i>\u00a0that it has not received any requests for a challenge inspection.<\/p>\n Can science help to verify a suspected attack?<\/strong><\/p>\n The OPCW would be called on to verify any allegations of a chemical weapons attack. Even without direct access to the war zone, the organization can gather evidence, in particular from satellite imagery and medical reports, Trapp says. \u201cIf there are victims, you will see victims being treated in medical facilities.\u201d And their symptoms and medical records would give clues.<\/p>\n Chemical weapons vary greatly in how they work and the types of evidence they leave behind. If inspectors have direct access in the immediate aftermath of an attack, they could collect samples \u2014 such as the by-products that nerve agents leave in the blood, or trace residues in the environment. In some situations, evidence collection could be more difficult; for instance, a chlorine attack might be hard to prove, because the gas can dissipate without leaving any trace.<\/p>\n There is precedent for this type of inspection, Trapp says: during the Syrian civil war, OPCW inspectors collected evidence in a war zone for the first time and reported that both chlorine and nerve agents had been used \u2014 something the Syrian government has denied. The inspectors did so at considerable risk, and came under fire\u00a0in at least one incident<\/a>.<\/p>\n More recently, the organization has tested methods for remotely gathering evidence from the site of a chemical attack. Researchers are exploring the use of a land or aerial drone to collect samples or even analyse them on site.<\/p>\n![\"\"](\"https:\/\/www.fie.undef.edu.ar\/ceptm\/wp-content\/uploads\/2022\/04\/d41586-022-00948-0_20280654.jpg\")