In the movie Sunset Boulevard Gloria Swanson plays a Hollywood has-been who pathetically deludes herself that she is about to be recalled from retirement to star again on the silver screen. In a deeply poignant scene she fantasises that the paraphernalia of film-making has once more been assembled for her big moment. “All right, Mr DeMille, I’m ready for my close-up.”

President Vladimir Putin of Russia seemed to be going through a similar moment of self-deceiving nostalgia when he warned the West last week that he would return to the former practice of targeting his country’s nuclear weapons on European cities. What role did he think he was playing? Nikita Khrushchev, circa 1962?

It is a long time since we needed to give serious thought to Russian missiles hurtling through the air towards us. Stripped of its communist ideology Russia lacks the zeal to commit itself to a war in which it would be annihilated. Since the collapse of the Soviet Union its once-celebrated military prowess has been revealed in a series of disasters to be more akin to a music-hall joke.

Russia retains formidable stocks of nuclear warheads and recently tested an impressive new intercontinental missile to carry them vast distances. But since those weapons are too terrible to be used, possessing them gives Russia little leverage in world affairs. Like the fearsome dragon in Wagner’s Siegfried, Russia can merely sit and brood upon its awesome power. It is of no practical use.

What Russia does still concerns us. Its descent into dictatorship is depressing. Its dominant position in energy supply gives it some clout (though it needs to sell its oil and gas at least as much as we need to buy them). If the Russian authorities are behind the fatal poisoning in London of Alexander Litvinenko, the former spy, they have committed an outrage. Russia’s permanent seat on the United Nations security council gives it the power to be a nuisance, as it has been by resisting effective sanctions against Iran. But whatever anxieties Russia may cause us, the thought that it might fire its warheads is not among them.

Perhaps Russian voters, preparing to choose a new president in the spring, are impressed by Putin’s bluster. They yearn for Russia to play the role in world affairs to which, they believe, its size and history entitle it. The untamed growth of capitalism under Boris Yeltsin and the rampant rise in energy prices during Putin’s tenure have given Russia a fragile illusion of success. If Putin also wishes to posture to domestic audiences about Russia’s nuclear potency it may be no more harmful (probably less) than Tony Blair’s reveries about saving Africa or imposing democracy on some of the globe’s benighted nations.

The president’s threat to point his missiles at Europe could have been met in the West with contemptuous indifference or a guffaw. In fact both George Bush and Blair cautioned him against reviving cold war rhetoric.

They should be so lucky! The nuclear stand-off of yesteryear has as much nostalgic attraction for the West as for Russia. In those good old days nobody defied the superpowers and the exclusive nuclear weapons club. It was also easier to be a hero. Pressuring the Soviet Union until it imploded made the careers and legacies of Ronald Reagan and Margaret Thatcher. Little wonder, then, that last week their successors reached for the old scripts of the cold war screenplay.

The West, too, feels impotent squatting on its hoard of nukes while all around events spin out of control. Its thousands of warheads did not protect the US against the attacks of September 11, 2001. Since this century began the world’s destiny has been shaped less in Moscow and Washington than in the cave where Osama Bin Laden hides and plots.

America’s military technology has not prevented it from becoming bogged down in Iraq. May was the worst month yet for American fatalities there. Perhaps Saddam Hussein laughs from beyond the grave at the trap into which he lured us. Deposing him has cost us dear in lives, but still more in credibility and prestige.

The one remaining superpower, America, is now mesmerised by Iran, rather like a bull plagued by a gnat. Before, the ayatollahs were held in check by Saddam, but we removed him. Now Iran kills, directly or indirectly, American and British soldiers. In response Washington can choose only whether to fulminate or parley.

The only question left in Iraq is whether we maximise our defeat and Iran’s triumph by staying or quitting. The moral price we have paid is equal to our strategic losses. Responding to criticisms of his human rights record Putin was able to cite Guantanamo Bay and “extraordinary rendition” as counter examples of western violations.

Even last week Blair said he sympathised with Putin’s problems in Chechnya. Really? Hundreds of thousands of people have died in the savage war between Russia and its troublesome satellite, and Grozny, the Chechen capital, has been flattened. Blair’s sympathy indicates that the “war on terror” now justifies almost anything. As a matter of policy we do not count the number of Iraqis who have died since the allied invasion. The figure does not match Chechnya yet but it is building steadily.

Moral compromise is the order of the day. While we protest to Moscow about its infringements on democratic values, we ingratiate ourselves with autocratic Saudi Arabia, Pakistan and Uzbekistan. Of course we do, because in our weakness we rely on the survival of those regimes, whatever their character, which will help us in the struggle with militant Islamists.

The West’s powerlessness has been demonstrated well beyond the Gulf. We watched helplessly as India, Pakistan and lately North Korea acquired nuclear weapons. But in this domain, at least, we have a technological fix. America’s antiballistic shield will deal with small numbers of warheads launched by a rogue state. The American missiles to be installed in Poland and their linked radars in the Czech Republic will be well located to intercept rockets from Iran.

From Iran? Why would America need to plan against Iranian missiles given that Bush has set himself against allowing Tehran to acquire the bomb? Last week the Republican party’s potential presidential candidates bravely contemplated using tactical nuclear weapons to destroy Iran’s centrifuges before they can start spinning.

That is another fantasy. Exhausted by the Iraq war, the American people will not accept another foreign adventure. America faces no direct threat from an Iranian warhead and could intercept it even if it did. It seems that military planners at least have prepared for Iran shortly to go nuclear, despite strenuous US opposition, just as North Korea has. The rational response is indeed for America to neutralise the threat using its vastly superior technology.

If America as a superpower is down, Russia as a superpower is out. What could be more humiliating than to watch America implant its military hardware in the former Soviet puppet states? In the early postSoviet days, when I was defence secretary, Nato used to pussyfoot around Russia, trying not to make it feel too bad about being weak. Those times are gone and Warsaw and Prague now flaunt their (limited) role in the defence of the West. Naturally, Putin feels provoked.

Part of Blair’s legacy will be that he ordered the renewal of Britain’s nuclear deterrent (though it cannot conceivably ever be used). The only reason for updating it is that it supposedly buys us influence. The rather pathetic figure that Russia cuts in the world today, despite having vastly more warheads than Britain, shows that that argument is overstated.

The case for an independent British deterrent rested on the existence of the USSR. Blair’s policy is another example of nostalgia. Last week came news of a Polish man who has woken froma coma that he had entered when his country was still communist. You have to wonder whether Blair has been fully conscious during the past two decades. Maybe like Putin he fantasises that the Soviet threat still exists.

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