SALISBURY, England — The U.K. government’s response to the botched poisoning of a defected Russian spy in 2018 basically gave Vladimir Putin a green light for more attacks, says one of the Kremlin’s most influential critics.

It's been one year since the nerve-agent attack in a Salisbury park that killed a member of the public and put ex–double agent Sergei Skripal and his daughter, Yulia, in the hospital for weeks. And though the British government identified two Russian agents as the alleged perpetrators and expelled Russian diplomats over the incident, Bill Browder thinks further sanctions would have been the right deterrent, considering the Kremlin's pattern of attacking its enemies.

“The only consequence to Russia using military-grade chemicals in Salisbury to assassinate their enemies is 23 diplomats being expelled,” said Browder, a financier and activist who's waged a long campaign against Russian corruption after his own experience in Moscow in the 1990s. “Effectively, Vladimir Putin has been given a message by the British government: that he can get away with murder.”

The U.S.-born hedge fund manager, once one of Russia’s biggest foreign investors, was kicked out of the country in 2005 after his lawyer accused the Kremlin of stealing from Browder's firm. The lawyer, lawyer Sergei Magnitsky, died in jail after uncovering massive tax fraud implicating Russian officials. Magnitsky's name, Browder successfully lobbied Congress to pass the Magnitsky Act, which sanctions individuals linked with human rights abuses.

VICE News talked to Browder about his ongoing worries over Putin's tactics.