Navalny's top aide told the Guardian that Ukraine shows Putin is crazier than they thought.
Putin "doesn't care about sanctions, about international reaction," Leonid Volkov said.
Volkov warned Navalny's survival could depend on whether Putin sees him as a bargaining chip.
Alexey Navalny's survival is at risk, according to the imprisoned Kremlin critic's top aide, who warns that Russian President Vladimir Putin is crazier than they previously assessed.
Before Russia invaded Ukraine, Navalny's team believed Putin would not want to risk seeing the opposition leader die in prison because the world was watching closely and the Kremlin would be blamed. But Navalny's top aide, Leonid Volkov, told the Guardian that Putin's handling of the Ukraine war has changed their view of the Russian leader.
"Our assessment of how crazy Putin actually is was wrong," Volkov said, emphasizing that the Russian leader "doesn't care about sanctions, about international reaction."
The war in Ukraine has largely made Putin an international pariah, while isolating Russia both economically and politically. Countries across the world have condemned Russia's unprovoked invasion, which has seen Russia slapped with unprecedented sanctions. And despite the fact the war has also not gone well for Russia, which has suffered astonishing casualties over the course of the conflict, Putin has shown no signs of giving up on his goal of subjugating Ukraine.
But if Putin ever turns to negotiations to end the war, Volkov is hopeful that Navalny could be seen as a bargaining chip.
"Putin is not very much in touch with reality apparently, but even he thinks about possible future scenarios. Under such circumstances Navalny is a potential bargaining chip. This could also be important," Volkov said.
Navalny, who has continued to be a vocal critic of Putin while in prison and has called for mass protests against the Ukraine war, said last week he was transferred to solitary confinement in order to "shut me up."
In tweets via an intermediary, Navalny urged people to campaign against the Ukraine war and Putin "at every opportunity."
The Russian opposition leader's health has been a constant source of concern during his time in prison. Volkov expressed concern over Navalny's condition and ability to continue communicating now that he's in solitary.
"Now the situation is, I have to admit, very bad, because now his communication with the outside world is very limited, and his health is endangered and his physical condition might get worse," Volkov said. "We have to keep talking about Navalny," he added.
Navalny, who is Putin's most prominent critic, was poisoned with a Soviet-era nerve agent in Siberia in August 2020. Putin has been widely blamed for the incident, which nearly killed Navalny. The Russian leader has denied any involvement.
After receiving treatment in Germany for several months following the poisoning, Navalny returned to Moscow in early 2021 and was promptly arrested. The Russian opposition leader was thrown behind bars on charges condemned across the world as politically motivated and has since seem time tacked on to his sentence. Navalny's imprisonment led to mass protests in 2021. Last June, Volkov told Insider that Putin was "dumb" to throw Navalny in prison because it turned the anti-corruption campaigner into a symbol for Russians to rally behind.