Writing in the Daily Mail, Economist correspondent and Russia blogger Edward Lucas again lets the malignant little troll in the Kremlin have it with both barrels:

There was an old dictum of Cold War propaganda operations that instructed agents to: "Admit nothing. Deny everything. Make counter-allegations." Such a hostile approach to international relations seems almost comical in our more enlightened age. But now it appears those same aggressive tactics have been dusted off for use by a new generation of Kremlin goons. How else can we explain the bizarre press conference held yesterday by Andrei Lugovoi (pictured, above), the man whom British authorities have formally named as the man they believe murdered Russian dissident Alexander Litvinenko in London by contaminating his tea with a radioactive isotope?

Lugovoi now asserts that he has been set up by the British security services, that Litvinenko was in the pay of MI6, and that they had tried to recruit him, too, to help discredit Putin and his cronies. All very intriguing. And all fabrication. The truth is that from the start of the saga surrounding Litvinenko's death, Russia has done nothing to help clear up the many mysteries in the affair, and everything to stonewall, distract and mislead both investigators and the outside world. Let us remember that the Kremlin's immediate response to Litvinenko's death was to blame Boris Berezovsky, the London-based billionaire tycoon.

The argument was as simple as it was preposterous: Mr Litvinenko's demise had made Russia look bad. Mr Berezovsky is an enemy of Russia. Hence, Mr Berezovsky must be behind the murder. Yet astonishingly, some in the West were initially prepared to believe there might be something in that far-flung theory. Mr Berezovsky is certainly viewed as a troublesome guest in Britain - he owes his right to stay here to a murky deal in which he brokered the release of two British citizens kidnapped in Chechnya. His increasingly vocal criticism of Mr Putin's regime, including demands for it to be overthrown "by force", is an unpleasant reminder of the way in which Russia's internal power struggles now spill over into Britain. But no serious evidence connected him to Mr Litvinenko's death.

By contrast, huge unanswered questions surround the mysterious Andrei Lugovoi and his friends, who had left a trail of polonium across half of western Europe before their ill-fated tea-party with Mr Litvinenko in London on November 1 last year. And those unresolved questions were becoming a thorn in the Kremlin's side. Specifically, they risked undoing the work of the Russian authorities and big Russian companies who have splurged millions of pounds on PR companies to schmooze politicians, journalists and officials to dispel notions that Russia is effectively a fascist gangster state, run by ex-KGB thugs and riddled with crime and corruption. They were aided and abetted by greedy foreign bankers and brokers, who are determined that nothing should derail the spectacular gas-fired gravy train that trundles between Moscow, Frankfurt, London, and New York, dribbling fees and profits as it goes.

Never mind about the crime and extortion, they murmur. Look at the money. Give Russia a bit of time. What's one murder here or there? Yet the oily charms of the Kremlin chorus could not silence the clamour created by Litvinenko's assassination. Even those who found the victim's past murky could not ignore the fact a British citizen was murdered in broad daylight on the streets of London, and that the lives of at least 17 wholly innocent residents of the city were endangered by the astonishingly casual and callous conduct of the poisoners. And when Mr Lugovoi was formally charged by the Crown Prosecution Service, the Kremlin responded by refusing the request for his extradition, and has now embarked on a shameless and cynical counter-attack. Whether or not Mr Lugovoi was involved in the squalid saga under their direct control from the start, he is certainly working to their instructions now, spewing out ever more bluster and confusion.

Contrary to Lugovoi's wild claims, all the evidence suggests that MI6 was never even interested in Mr Litvinenko as a source of information. He had to organise his own escape from Moscow in 2001, using a clumsily forged passport. That does not suggest that any Western intelligence service was behind his departure. Had they been so, he would have been "exfiltrated" with great professionalism and secrecy. Similarly, when he arrived at Heathrow airport, no British officials were waiting for him: indeed, he found it hard to get into the country at all. Even after that, the British authorities showed little interest: had they done so, he would have joined Oleg Gordievsky, Vasily Mitrokhin, Vladimir Rezun, Vladimir Kuzichkin and other top defectors from the Kremlin's intelligence services, expensively provided with closely guarded new identities, jobs, housing and pensions courtesy of the British taxpayer. In fact, Mr Litvinenko lived publicly and rather poorly in North London, dependent on a small stipend from Mr Berezovsky and occasional consulting work. It is marginally more possible that MI6 would have been interested in Mr Lugovoi himself, as he alleged yesterday. It is impossible to prove or disprove. But it beggars belief that they would have discussed Mr Litvinenko with him, as he now claims. Secret services are notoriously grudging with information even inside the organisation, and certainly do not chat freely with their newly recruited sources. It is possible in theory that the British authorities might have belatedly decided to use Mr Litvinenko for some reason. But again, it is hardly likely. The whole thing would strain the credulity even of the most jaded consumer of spy fiction.

So why does the Kremlin think these lies are worth peddling? Many people around the world believe that the British intelligence services are both supremely devious and supremely ruthless; it will be all too easy to convince the paranoid and gullible that it was the agents of the hated, duplicitous British state that murdered Mr Litvinenko, rather than anyone connected with the muchmaligned Vladimir Putin, whose only crime is to stand up against the Anglo-American drive for world domination. In short, the most likely explanation of Mr Lugovoi's bizarre allegations are that the Kremlin dezinformatsiya machine has just moved up another gear. It certainly fits a pattern: the Kremlin has returned to the authoritarian and xenophobic habits of the past in a way that the West is still pitifully unwilling to confront.

Russia's rulers care nothing for solving the Litvinenko case. Instead, they have decided to cynically exploit the tragedy. The big question for the West is whether this combination of deceit and ruthlessness is merely the temporary revival of Soviet-era habits, or whether it presages the terrifying descent into a new Cold War.