In April and May 1979, between 66 and 300 people died from anthrax in the Russian city of Sverdlovsk, now called Yekaterinburg. The Soviet authorities seized doctors’ records and quickly rolled out an explanation: the deaths were an accident caused by contaminated meat.

But American intelligence agencies suspected a more nefarious explanation: the Soviets were secretly developing biological weapons.

Last week, we interviewed Matthew Meselson about his key role in convincing Henry Kissinger and Richard Nixon to ban biological weapons research in the early 1970s. After the Sverdlovsk incident, Meselson was brought in by the CIA to help assess the potential explanations. For more than a decade, he led scientific investigations into the incident. In 1992, after the fall of the Soviet Union, the truth finally came out: the Sverdlovsk incident was a bioweapons lab leak, the most deadly confirmed lab leak in history.

Meselson’s paper confirming the lab leak is an epidemiological classic. For the first time on Statecraft, we’ve doubled up on a guest: the 94-year-old Meselson is back for round two.

[00:00] The CIA recruits Meselson

[5:38] Attempts to travel to Sverdlovsk

[9:11] Meselson travels to Moscow

[14:15] An invitation to Sverdlovsk

[25:27] On-the-ground investigation

[34:25] Who knew what, and when did they know it?

[40:16] Who is developing chemical weapons today?

[45:34] How closely does the Sverdlovsk lab leak parallel incidents in Wuhan?

[50:31] Why the Soviets couldn't find their own research facilities