Critics see Moscow's hand in the poisoning, while Putin supporters point to an anti-Russia conspiracy.
The mysterious London poisoning death of an exiled former KGB agent, who accused the Kremlin on his deathbed, has set off an emotionally charged debate over who's to blame and what it means for the future of Russia under President Vladimir Putin.
Some fear the country's unreformed secret services may be returning to their old methods of eliminating real and imagined enemies. But many defenders of Mr. Putin claim the slain spook's allegations are evidence of a sophisticated anti-Russian conspiracy at work.
Alexander Litvinenko, who died Thursday after ingesting a rare radioactive substance used mainly in space programs, was an outspoken critic of the Kremlin and a close ally of exiled tycoon Boris Berezovsky, a vociferous Putin foe.
In a terse statement last week, the Kremlin dismissed allegations of its involvement as "sheer nonsense" and offered to help British investigators with their inquiries into the alleged murder. But experts say it's not surprising that many people have been quick to assume that the former KGB must have had a hand in it. Experts say that's not surprising.
"In Russia we have secret services that were, not long ago, involved in mass arrests and executions of political opponents, and most of this they kept secret," says Alexei Simonov, head of the Glasnost Defense Foundation, an independent media watchdog. "People in this country tend to blame power for everything that happens, and they have their reasons," he says.
Some experts argue that old cold-war biases that no longer apply to Russia are behind the rush to condemn the Kremlin.
"Russia has changed, it is not the Soviet Union anymore," says Sergei Markov, a Kremlin- connected analyst. "The security services were totally reformed in the 1990s, and it is not possible for them to carry out the kind of actions they're being accused of," he says.