Writing in the UK's Daily Mail, the brilliant Russia pundit (and ace blogger) Edward Lucas lets the neo-Soviet Kremlin have it with both barrels:

Murder on our streets. Blackmail over oil supplies. Cyber-terrorism. Putin's Russia poses a grave threat to our way of life.

So now it's official: the nuclear terrorist attack on the streets of London that killed Alexander Litvinenko and contaminated 17 others was not by 'person or persons unknown'. The British authorities have publicly named the man many have long seen as the prime suspect: Andrei Lugovoy, a multi-millionaire ex-KGB agent with close ties to the Kremlin. His trail leads through London and Hamburg, marked by traces of Polonium-210, the lethal radioactive isotope that condemned the Russian defector to a grisly death.

Many mysteries remain.

Mr Lugovoy vehemently protests his innocence. Was he set up by the real assassins? Or was he a bungler? Professional KGB killers would never have left so many clues. Maybe the Kremlin wanted to send a powerful message, condemning a man they saw as a traitor to a slow, agonising and public death? And how serious was Mr Litvinenko, with his increasingly wild allegations of paedophilia in the Kremlin and Russian support for Al-Qaeda?

In spy novels, such puzzles are neatly unravelled by the end of the story. But this real-life thriller has only just begun, and there are few answers to any of the terrifying problems that it poses. The truth is that Russia, under Vladimir Putin, has become a nation that matches the resources and ambition of a superpower with the ruthlessness and ingenuity of gangsters and terrorists. As even the most sentimental and feeble-minded westerners are beginning to realise, Russia poses a profound threat to our way of life, and one that we are still pitifully ill- equipped to counter.

The first and most blatant weapon in its armoury is murder. As Paul Joyal, a prominent American expert on intelligence and Kremlin dirty tricks - and a friend of Mr Litvinenko's - said on an American television programme: "A message has been communicated to anyone who wants to speak out against the Kremlin: 'If you do, no matter who you are, where you are, we will find you and we will silence you - in the most horrible way possible.' "

A week after that interview was broadcast, Mr Joyal was gunned down outside his home near Washington DC. Initial reports said it was just a sinister coincidence. Mr Joyal himself, his internal organs torn to pieces by the attacker's bullet, was in a drug-induced coma for nearly a month. Since then he has said little. But when I spoke to him, he said that the behaviour of the attackers and the fact that they left his wallet, briefcase, computer and car (as well as other objects that must stay confidential for now) mean it is virtually impossible that it was mere street crime. That suspicion might also be shared by America's FBI, which - highly unusually - is assisting the local county police in their investigation.

Kremlin death squads have killed others.

Zelimkhan Yandarbiyev, an exiled Chechen leader, was blown up in February 2004 in the Qatari capital, Doha, along with two bodyguards and his young son. The perpetrators - officers in Russia's elite GRU military intelligence service - were caught, tried and imprisoned. As part of a deal with Russia, they were returned home, supposedly to serve out the rest of their sentences. Instead, they received a heroes' welcome and were released.

So much for legality in Russia, a country that has passed a law authorising the murder of its enemies abroad. The definition of enemies, incidentally, includes "extremist" - a word that Russian officials use to describe anyone who disagrees with them. Russia shows a similarly cavalier attitude to its business dealings with the outside world. Tearing up contracts without the slightest hesitation, it uses blackmail against its neighbours in a way that would have been unimaginable even in the depths of the Cold War.

Lithuania and Estonia, two brave Baltic nations that cast off the shackles of communist tyranny in 1991, are in the front line of Russian energy sanctions. A vital oil pipeline to Lithuania's Mazeikiai oil refinery - the mainstay of that country's economy - has been cut off, supposedly for urgent maintenance. But the repair works have been going on for nearly a year and are set to continue indefinitely.

When Lithuanian officials protested, a senior Russian visitor told them: "Sorry, you should have sold the refinery to us" (Lithuania had sold it to the main oil company in friendly, neighbouring Poland). Among other sanctions on Estonia, Russian officials have crippled trade by closing that country's main road bridge from Russia, again claiming that it needs "urgent repairs". Given Europe's dependence on Russian energy, that is already alarming. But it is another kind of onslaught unleashed against plucky Estonia that has set deafening alarm bells ringing in Brussels and Washington. Last month, Estonia's government decided to move a Soviet war memorial in the centre of the capital, Tallinn, to a nearby military cemetery. That prompted demonstrations by local Russians, egged on by the Kremlin's spies and provocateurs, which soon turned into riots and looting.

In the chocolate-box streets of medieval Tallinn, familiar to many British holidaymakers as one of the friendliest and most charming capitals of Europe, drunken Russian hooligans emptied shops and burnt cars, chanting "It's all ours" and "Soviet Union for ever". In Moscow, thugs blockaded and attacked the Estonian embassy - a flagrant breach of the Vienna convention. When the Swedish ambassador visited, they tried to turn over his car. But that was only a taste of the havoc to be wreaked in cyberspace. Estonia's most vital computers experienced a cyber-attack on a scale and ferocity unknown in the history of the internet. Techniques normally employed by cyber-criminals, such as huge remote-controlled networks of hijacked computers, were used to cripple vital public services, paralyse the banking system and cut off the government's websites from the outside world. By cutting Estonia off from the world, the Kremlin's propagandists could freely peddle their poisonous lies about a "fascist revival" in this peaceful, prosperous and democratic country.

Luckily for us, Russia's goons and spooks have overplayed their hand. Outrage in Germany about the way Vladimir Putin's thuggish regime crushes opposition and bullies its neighbours makes it easier for the steely Chancellor, Angela Merkel, herself a former inmate of the grim Communist prison camp of East Germany, to show her own distaste. The European Union's summit with Russia in Samara last week was a frosty affair - a welcome change from days of Silvio Berlusconi, Jacques Chirac and Gerhard Schroder, infamous for their sleazy backslapping with Russia's leaders.

But we in Britain have yet to catch up - thanks, paradoxically, to our open, globalised economy. Russia's energyfuelled wealth has given it a vital bridgehead, creating a powerful lobby of banks and business partners that overlooks any crimes in the hope of profit. BP's imminent loss of its most prized investment in Russia, the $6 billion Kovykta gas field, is a punishment for the British authorities' temerity in charging Mr Lugovoy. That shows how high the stakes are.

Even now, the Kremlin's slimy spin-doctors are trying to downplay the Litvinenko murder: he was a "provocative" figure, one of them murmured to me. But since when has being "provocative" attracted a death sentence, meted out without judge or jury on the streets of London? The dismal truth is this: during the Cold War, capitalists and freedom-fighters were on the same side. Now that Russia has adopted capitalism - albeit its own barbarous version - a fifth column has marched straight into the heart of the British establishment.

What will it take to counteract it?