Soviet Union Secretly Stockpiled Biological Weapons, Newly Revealed Files Show

Newly revealed documents indicate that the Soviet Union secretly developed and stockpiled biological weapons while publicly denying their existence, a history that has resurfaced as experts question Russia's handling of an unexplained death at a plague research institute. Darya Shipilova, 28, a worker at the Irkutsk Anti-Plague Research Institute in Siberia, died on October 2. Russian authorities have stated her death was due to pneumonia of unknown origin, but approximately 200 of her contacts were placed under medical observation. The World Health Organization was informed by Russian health officials that no plague cases were recorded in Irkutsk.

Experts have noted that the Soviet Union historically operated an offensive biological weapons program, and some anti-plague institutes were part of this effort. A May 1990 report, sent to then-Soviet leader Mikhail Gorbachev and later published by the National Security Archive, acknowledged that biological weapons had been developed, produced, and stored. According to the report, Soviet organizations had developed 12 formulations and methods for their use by 1985. Earlier, in January 1990, Soviet Defense Minister Dmitry Yazov urged officials to retract a proposed disclosure about past stockpiles, arguing it would contradict Moscow's public denials.

While Russian officials have not confirmed plague as the cause of Shipilova's death, reports indicate she may have accidentally broken a test tube containing live bacteria. This incident has prompted concerns from biosecurity experts who question whether the institute might be investigating pathogens other than plague, given the institute's historical involvement in sensitive research and the Soviet Union's past secrecy.

According to the report sent to Gorbachev, Lev Zaikov, a Politburo member overseeing the Soviet military-industrial complex, stated that biological weapons development began in the 1950s and expanded to include 12 additional organizations by 1971. Zaikov claimed that by 1985, 12 weaponized agents were developed, produced in sufficient quantities, stored, and then destroyed after their shelf life expired. The Soviet Union had signed the Biological Weapons Convention in 1972, which entered into force in 1975, prohibiting the development, production, and stockpiling of biological weapons.

Zaikov's report, however, presented a narrative suggesting Soviet work was a response to alleged advances by NATO countries, which he claimed exploited loopholes in the treaty. He asserted that Soviet biological weapons research shifted toward defensive work in 1989 to comply with treaty obligations and that stockpiles were destroyed and industrial production ceased that same year. The National Security Archive described Zaikov's report as offering a "selective spin" on the program's history and suggested it showed Soviet officials had misled Gorbachev.

Further complicating the historical record, Vladimir Pasechnik, who headed a scientific organization in Leningrad, defected to Britain in October 1989 and began revealing details of the Soviet program. Zaikov's report acknowledged Pasechnik's knowledge but downplayed the potential damage to Moscow's compliance claims.

In a January 10, 1990 memo, Defense Minister Yazov opposed sharing information with the U.S. about past biological weapons stockpiles and production sites, fearing it would contradict official denials. He also rejected acknowledging a laboratory accident during the 1979 anthrax outbreak in Sverdlovsk, which the Soviets had attributed to foodborne sources. A 1994 investigation later concluded the outbreak was caused by airborne anthrax released from a military facility.