Imprisoned Russian opposition politician Vladimir Kara-Murza said in an exchange of letters with blogger Anna Yarovaya that Russian President Vladimir Putin’s rule is based “exclusively on fear and apathy,” and will collapse in the “foreseeable future.”

The 42-year-old is serving a 25-year prison term on charges of high treason and discrediting the Russian military involved in Moscow’s ongoing invasion of Ukraine, which he, his supporters, and human right groups reject as politically motivated.

Kara-Murza wrote in the letters, published on the Yarovaya pishet Telegram channel over the weekend, that he was shocked by the news on February 16 about the death of another leading opposition politician, Aleksei Navalny, in an Arctic prison and had no doubt Putin was “personally responsible.”

“From the first second [after hearing the news] I knew for sure that Vladimir Putin was personally responsible for the death of Aleksei Navalny and that a political murder was carried out on his orders, no matter if it was the result of intentionally created torturous conditions or repeated poisoning,” Kara-Murza wrote, adding that he was not aware of how other inmates reacted to the news, as he is being held alone in a punitive part of the prison in the Siberian city of Omsk and has no contact with other inmates.

According to Kara-Murza, a credible politician cannot live outside the country, so opposition politicians such as himself and imprisoned Kremlin critics such as Ilya Yashin, Andrei Pivovarov, and Navalny, have no choice but to stay in Russia or return to Russia to challenge the authorities.

“For a public politician, it’s a question of ethics and political responsibility…. If you call on people to stand against the authoritarian regime, you cannot do it from a safe distance — you have to share the risks with your compatriots,” Kara-Murza wrote.

In one letter, he also wrote that as a historian he believes that history has its own developmental laws and logic that nobody can “cancel.”

“Let’s look at the map of Europe — just 35 years ago, half of the countries there were authoritarian. Today there are only two countries in Europe that are not free — Russia and Belarus. And there is no doubt that these two bastions are also temporary,” Kara-Murza stressed.

“I absolutely have no doubt that in the very foreseeable future, Russia will become a democracy, or as Aleksei Navalny liked to say, ‘a normal European country.'”

“Putin’s regime is based exclusively on fear and apathy. The authorities want Russian society to be divided, depressed, demoralized,” Kara-Murza wrote.

“But you remember what Aleksei Navalny said…. The changes will not come to Russia from outside…. Only when Russian society itself stops tolerating what is going on, when it realizes its strength, its identity, and its responsibility for the future, the changes in Russia will become inevitable. When that happens depends solely on us,” Kara-Murza wrote.

Kara-Murza, who holds Russian and British passports, was initially arrested in April 2022 after returning to Russia from abroad and charged with disobeying a police officer.

He was later charged with discrediting the Russian military, a charge stemming from Russia’s 2022 full-scale aggression against Ukraine and a Kremlin push to stamp out criticism of the subject. He was later additionally charged with treason over remarks he made in speeches outside Russia that criticized Kremlin policies.

In April last year, Kara-Murza was found guilty of all charges and sentenced to 25 years in prison.

Kara-Murza fell deathly ill on two separate occasions in Moscow — in 2015 and 2017– with symptoms consistent with poisoning.

Tissue samples smuggled from Russia to the United States by his relatives were turned over to the FBI, which investigated his case as one of “intentional poisoning.”

U.S. government laboratories also conducted extensive tests on the samples, but documents released by the Justice Department suggest they were unable to reach a conclusive finding.

The Kremlin has denied any involvement in the incidents but investigative reporters from Bellingcat, The Insider, and Der Spiegel say they have identified four Federal Security Service (FSB) — Roman Mezentsev, Aleksandr Samofal, Konstantin Kudryavtsev, and Valery Sukharev — who followed Kara-Murza secretly during his trips before both times when he fell ill.