IT WAS outrageous enough that a deadly nerve agent was used in an assassination attempt against Russian opposition leader Alexei Navalny, who survived. But the story is not over. Now, a group of news outlets has exposed what they describe as clandestine Russian organizations carrying out illegal chemical weapons development concealed as civilian research.

If these reports are true, they add a major dimension of concern to the attempted killings of Mr. Navalny in August and former military intelligence officer Sergei Skripal and his daughter in March 2018 in Salisbury, England. The Chemical Weapons Convention prohibits the development, production, acquisition, stockpiling, retention, transfer or use of chemical weapons. President Vladimir Putin says Russia has strictly adhered to its commitments under the treaty, but these reports suggest otherwise.

The reports are by the open-source investigations outfit Bellingcat; the Insider, a Russian news organization; Germany’s Der Spiegel; and the Russian service of Radio Free Europe/Radio Liberty. They found cellphone and text message logs that point to previously unknown involvement of two organizations and several scientists in the use of Novichok, a class of nerve agents created by the Soviet Union in the last years of the Cold War, against the Skripals. The news organizations reported that the St. Petersburg State Institute for Experimental Military Medicine of the Ministry of Defense, as well as the Scientific Center Signal, had taken the lead in weaponizing Novichok agents. Neither of these two organizations was cited in the recent European Union and British sanctions against Russia in response to the attack on Mr. Navalny.

The news organizations say the two research groups closely coordinated with a black-operations unit of the GRU, Russia’s military intelligence, that carried out the poisoning attempt on the Skripals. They report that Scientific Center Signal may have helped reformulate the Novichok agents to improve the rate and speed of absorption of the poison, as well as make it easier to deliver clandestinely. The news reports reinforce a conclusion made in 2018 by Mark Sedwill, then the British national security adviser, who said after the Skripal attempt that Russia had started a program to “test means of delivering chemical warfare agents and to train personnel from special units” in their use, and that Russia subsequently investigated “ways of delivering nerve agents, including by application to door handles.”

While the Chemical Weapons Convention has allowances for developing antidotes and defenses against chemical weapons, actually producing and using Novichok to poison the Skripals and Mr. Navalny are treaty violations. Recently, the European Union and Britain acted, but the Trump administration remains strangely silent about sanctions in response to the Navalny attack. Bipartisan groups of lawmakers in the House and Senate are urging a tougher response. Both the E.U. and the United States should investigate the newly identified research organizations. When the states parties to the treaty meet Nov. 30 to Dec. 4, they should consider a strong response.

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