TALLINN, Estonia — When Maksim Kolker's phone rang at 6 a.m., and the voice on the other end said his father had been arrested, he thought it was a scam to extort money. A day earlier, he had taken his father, prominent Russian physicist Dmitry Kolker, to the hospital in his native Novosibirsk, when his advanced pancreatic cancer had suddenly worsened.
The phone kept ringing and Kolker kept hanging up until finally his father called to confirm the grim news. The elder Kolker had been charged with treason, the family later learned, a crime that is probed and prosecuted in absolute secrecy in Russia and punished with long prison terms.
Treason cases have been rare in Russia in the last 30 years, with a handful annually. But since the 2022 invasion of Ukraine, they have skyrocketed, along with espionage prosecutions, ensnaring citizens and foreigners alike, regardless of their politics.
That has brought comparisons to the show trials under Soviet dictator Josef Stalin in the 1930s.
The more recent victims range from Kremlin critics and independent journalists to veteran scientists working with countries that Moscow considers friendly.
These cases stand out from the crackdown on dissent that has reached unprecedented levels under President Vladimir Putin. They are investigated almost exclusively by the powerful Federal Security Service, or FSB, with specific charges and evidence not always revealed.
The accused are often held in strict isolation in Moscow's notorious Lefortovo Prison, tried behind closed doors, and almost always convicted, with long prison sentences.
In 2022, Putin urged the security services to ''harshly suppress the actions of foreign intelligence services, promptly identify traitors, spies and saboteurs.''