In cyberspace, on the front line of the new Cold War, things appear to be hotting up. I say “appear” because a tablespoon of scepticism wants adding to the pot when the security services of a country as hooked on grandstanding from a position of weakness as this one leak stories designed to scare the enemy.

Nonetheless, today’s Sunday Times splashes with the exhilarating news that the UK has war gamed a cyberattack on Moscow with the capacity to “put the lights out in the Kremlin”.

How petrified Vladimir Putin will be is hard to quantify. He might summon the smelling salts, and then dispatch his best GRU guys (not the chumps caught in the act in Salisbury, possibly, or the Netherlands) to the basement to check out the diesel generator.

Theresa May: Russia 'flagrantly' violating international norms

Then again, he might chucklingly dismiss this as a typically empty threat from a nation that may remind him of his own in one respect at least. Watching Russia and Britain trash-talking each other is like being at the press conference before a bout between two geriatric heavyweights – once mighty, but paunchy and arthritic now – poised to fight for a tragically meaningless belt.

This rumbling Anglo-Russian bust up feels like a heritage clash; a pantomime pastiche of past glories on the geopolitical undercard before the main event to come between the real contenders, the US and China, for the undisputed crown.

No one ever claimed losing an empire, with all the phantom limb agony and crushing sense of irrelevance, was easy. Britain has had 70 years to work on it, and here we are pitiably trying to reenact that defiant little island standing alone in 1940 scenario with Brexit.

And almost 30 years after the disintegration of the USSR, here is Russia with an economy barely half the size of Britain’s, staring into a bleaker future with the value of her oil and gas reserves coming under relentless pressure from the rise of renewables. Small wonder if she is raging against the dying of the light (if not the Kremlin lights) with a range of guerilla warfare tactics of which cyberwarfare has the most effective cost-to-chaos ratio.

But finally, hurrah, after all the years of appeasement typified by Theresa May’s efforts as home secretary to shut down the enquiry into Alexander Litvinenko’s radioactive demise, Britain is ready to retaliate (or at least to pretend to be willing) by using the same methods as the enemy.

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This has a nostalgic ring from the old Cold War. As Control puts it in John Le Carré’s masterwork The Spy Who Came In From The Cold, although the West will never be the aggressor “our methods and those of the opposition have become much the same. I mean you can't be less ruthless than the opposition simply because your government's ‘policy’ is benevolent, can you now?”

Well, no, although we could argue about the benevolence of foreign policy since the Berlin Wall came down. Some detect the faint whiff of chutzpah when those who claimed to equate invading Iraq with a touching display of humanitarian concern lecture Russia about its Crimean incursion and all the mischief-making in Syria. Some also wonder whether inflaming timeless Russian paranoia about the integrity of its borders by inviting its neighbours to join Nato was an inspired idea.

But whatever the strategic competence, regardless of morality, do we have the technical ability to be as ruthless as the opposition? And even if so, is there any real political will to use it at a time when the American president with whom a trade deal may urgently need striking doesn’t seem wildly keen to pick fights with the Kremlin?

Any suspicion that the big talk about a cyberattack on Moscow may be laughable posturing is deepened by simultaneous news about more conventional war-gaming. In the deserts of Oman this weekend, 5,500 British troops fought mock battles with pretend Russian tanks. This cut price £100m exercise also involved six Royal Navy ships (not the new aircraft carrier on which the American F-35s seem unable to land, but hey, let’s not fixate on the trivia) and eight Typhoon fighter jets.

I must say, it sounds tremendous. Half a dozen ships and eight warplanes. You could defeat Costa Rica with that. But then Costa Rica has no military.

The notion of Britain, with an army so shrunken since the humiliations in Basra and Helmand that it’s offering cash bribes to soldiers sacked for failing drug tests to reenlist, being a match for Russia is preposterous. Not as preposterous as the notion that two nuclear powers will ever fight a conventional war. But more than ridiculous enough, thanking you, for most tastes.

At some point, you hope against hope, the idiocy of play-acting at great power status to an audience with bulls**t-detecting antennae as acute as Putin’s would penetrate the skulls of even as wilfully obtuse a government as this one.

The same goes for this threat of cyberattack. Even if one were possible, it would be politically unthinkable to ratchet up the tension to the cyber equivalent of Defcon 2 (Cuban missile crisis level) without the support of the only Western nation with the wealth and technical sophistication to wage cyberwar.

So long as Trump is in the White House and any kompromat that may or may not exist is in the Kremlin safe, there is more chance of Theresa May partnering Anton du Beke to victory on Strictly with her Peter Crouch-does-Abba tribute act.