It’s a murder mystery that has the trappings of a Hollywood thriller: a former Russian spy turned Kremlin critic is granted asylum in Britain, ends up working for the British secret service, then dies after a mysterious poisoning in London in 2006.
And now, the British public inquiry in Alexander Litvinenko's death accuses Russian President Vladimir Putin of having "probably approved" the assassination.
But just what ramifications the inquiry's final report, authored by Sir Robert Owen, will have is an open question. While it lays out the best case so far for the Russian government's involvement in the assassination, the accused perpetrators remain largely beyond reach.
And although Britain could attempt to retaliate against Mr. Putin and the other FSB officers named in the report, doing so would impede any cooperation between Britain and Russia in tackling the conflict in Syria, where the stakes are higher.
Who was Alexander Litvinenko?
Mr. Litvinenko was born in Voronezh in 1962 and served in the Russian military where he rose to the rank of lieutenant-colonel. He reportedly joined the KGB in 1988 where he worked in the organized crime unit.
In 1994, he was assigned to investigate an assassination attempt on Boris Berezovsky, a wealthy Russian oligarch. The two became friends, according to Alex Goldfard, an associate of both men. Litvinenko began working for Mr. Berezovsky and his relationship with him would prove critical.
In 1998, while serving in the KGB's successor organization, the FSB, Litvinenko publicly alleged that he had been given orders to kill Berezovsky and told a news conference that the agency was highly corrupt. At the time, the agency’s director was Vladimir Putin.
With help from Berezovsky, Litvinenko fled into exile in 2000. Britain gave him asylum and eventually citizenship.
Litvinenko’s death on Nov. 23, 2006, came after weeks of illness that baffled his doctors. They finally traced his symptoms to a suspected ingestion of radioactive polonium-210, which is fatal even when ingested in small amounts. The element is difficult to obtain; foreign governments, including Russia and the US, are known to keep stockpiles.
It was revealed after Litvinenko’s death that he was a paid agent for MI6, Britain’s intelligence service, and was also working with Spain’s secret service to investigate Russia’s involvement in organized crime.
Before his death, Litvinenko was investigating the assassination of Russian journalist and outspoken Kremlin critic Anna Politkovskaya. Litvinenko wrote a book, “Blowing Up Russia: The Secret Plot to Bring Back KGB Terror,” implicating the FSB in terror attacks in Russia in the late 1990s that paved the way for Putin's rise to power and a second war in Chechnya.
Who killed Litvinenko?
On the day he fell ill, Litvinenko drank tea that was laced with polonium-210 at the Millennium hotel in London with two Russian men: Andrei Lugovoi and Dmitri Kovtun. Both Mr. Lugovoi, a former KGB agent, and Mr. Kovtun, a business associate of Litvinenko's with links to the KGB, deny any involvement in his death.
Lugovoi later became a deputy in Russia’s parliament, the Duma, which granted him immunity from extradition to Britain. He passed a lie detector test and maintains he was framed. He has accused MI6 of being responsible for Litvinenko’s death.
But Sir Robert concluded that while Lugovoi and Kovtun may not have been aware of the nature of the polonium-210, they placed it in the tea "with the intention of poisoning Mr Litvinenko."
Moreover, Sir Robert said he was sure that the pair "were acting on behalf of others" in poisoning Litvinenko. Specifically, he said there was a "strong probability" that they were being directed by the FSB, "probably" with the approval of both Nikolai Patrushev, then head of the FSB, and President Putin.
What do the inquiry's conclusions mean for the accused?
Probably not much. Lugovoi and Kovtun are both beyond reach of British authorities in Russia, and maintain their innocence. Although the British government has international arrest warrants out for both men, those have been in place for years now without result. The inquiry's findings will likely ensure neither man will travel anywhere that might comply with the British warrants.
The Russian government isn't about to extradite either man: It has roundly condemned the inquiry and its findings. The Russian ambassador to Britain called the way the case was handled "a blatant provocation," while a Foreign Ministry spokesperson said the inquiry was meant solely to "to demonize Russia, demonize its official representatives, its leadership."
UK Foreign Minister Theresa May did announce that Britain would freeze the assets of Lugovoi and Kovtun, and would consider "whether any further action should be taken, both in terms of extradition and freezing criminal assets."
What does the inquiry mean for British-Russian relations?
That is a far more challenging question.
Ms. May called Litvinenko's assassination a "state-sponsored" "act of murder" and "a blatant and unacceptable breach of the most fundamental tenets of international law and of civilised behaviour." But she added that Putin, as Russian head of state, is largely safe from a British response.
Now the British government is facing calls, both from the opposition and members of the ruling Conservative Party, to act harshly against Russia to underscore the seriousness of the crime.
Labour shadow home secretary Andy Burnham said the government's response was not "anywhere near enough in answering the seriousness of the findings," and that Britain should expel Russian agents from the country in response.
David Davis, a Conservative MP and former shadow home secretary, said that Britain should "go after the financial assets of Putin in the Bahamas and in Cyprus. Eventually you get to a point when with a dictator you have to draw a line as we did in the 30s."
But Britain's response will likely be impeded by the shared foreign policy concerns of both Britain and Russia, most particularly in Syria.
Crispin Blunt, Tory chairman of the foreign affairs select committee, told BBC News that "The world has to engage with him [Vladimir Putin]. We are dealing with unsavoury partners all over the world. That is part of the necessity of diplomacy."
The government has known this was a state-sponsored murder since 2007 ... Unfortunately we have no choice but to deal with the Russians where serious national and common interests are at stake. With hundreds of thousands of people now dead in Syria, bringing that civil war to an end is a clear common interest of both our states.