After Gordon Brown met Colonel Muammar Gaddafi at the G8 summit in Italy earlier this year he joked that he had discovered Michael Jackson alive and well. There is indeed an uncanny resemblance between the Libyan leader and the King of Pop. But it was not, of course, the singer who asked the Prime Minister to release the Lockerbie bomber. Michael Jackson is dead — and so now is the “special relationship” between Britain and the United States.

The row over the decision to allow Abdul Baset Ali al-Megrahi to return to Libya is the final nail in the coffin for the transatlantic bond first identified by Winston Churchill after the Second World War. Even Barack Obama abandoned his normal diplomatic tone to criticise the “highly objectionable” arrival of the bomber in Tripoli. Robert Mueller, the head of the FBI, said that the release of the man convicted of murdering 270 people on Pan Am Flight 103 made a “mockery of justice” and would give “comfort to terrorists around the world”. There was a widespread assumption in Washington all along that the decision was linked to a trade deal.

For the Americans, this is not just about justice it is also about trust — the White House sees the release of al-Megrahi as a blatant breach of an agreement given by the British Government that he would serve out his sentence in Scotland. It is impossible to sustain a relationship, let alone a special one, if one partner can no longer believe what the other one says. In Whitehall there are already nervous mutterings about whether intelligence-sharing and military co-operation will be able to continue in the same way.

This may be a tipping point but in fact the United States has been tilting away from Britain for some time. Ironically, at the very moment when people in this country are rediscovering after years of hostility their love of America — as a result of the election of the first black president — the Americans are tiring of their old European flame.

On holiday on Long Island this summer, I was struck by the anti-British mood. There are T-shirts for sale in New York with the slogan “Britain’s not that great” printed next to pictures of a helmeted policeman and Big Ben. “Your country is just a dipshit little nation,” an influential celebrity agent told me over dinner in the Monkey Bar (the fashionable Manhattan restaurant that is part owned by the British restaurateur Jeremy King). “It’s got no power or influence any more. I bet only 5 per cent of the people in this room have even heard of Gordon Brown.”

In different areas, antipathy towards Britain is taking hold just as anti-Americanism in this country fades. The debate about health reform in the US has been dominated by distorted accounts of appalling death rates and eugenic policies under the “evil” NHS. Meanwhile, the British Armed Forces are facing increasing criticism for what the Americans see as a failure to pull their weight in Iraq and Afghanistan. The City of London has been decimated by the credit crunch and could end up paying a heavier price than Wall Street as the new financial world order takes shape. Even London Fashion Week is a poor relation to similar events in New York, Paris and Milan.

There is a growing perception in the US that the UK is losing its way — with MPs who have been caught fiddling their expenses, a recession deeper than anywhere else and a leader who has become a lame duck. Newsweek, the magazine that hailed Cool Britannia in the 1990s, recently redefined us as “Little Britain”, a nation struggling to keep a foothold in a rapidly changing world. It used to be said that we punched above our weight — but now we have become the global punch bag as China and India rise. The new dawn is over, replaced by a gloomy dusk.

With budget cuts looming whoever wins power at the next election — particularly to the Ministry of Defence and the diplomatic corps — it looks like a pretty irreversible trend.

But it’s not just about money; it’s also about public image and prestige. As Barack Obama flew home after his first visit to London as President earlier this year, he gave aides his verdict on the three leaders he had met. David Cameron had “sizzle”, Mr Brown had “substance” but only Tony Blair had “sizzle and substance”. In America, they want politicians to be like Hollywood idols, and a leader who lacks star quality will find it almost impossible to break through.

It is ironic that after years of wanting what Mr Blair used to call a Love Actually moment — a British leader who would tell a US president to get lost — the public in this country now craves a Love-In Actually with the nation run by Mr Cool. But what we have got is a global version of this year’s romantic comedy He’s Just Not That Into You. Our politicians are like teenage girls trying to attract the attention of the high school heart-throb. They gaze adoringly across the Atlantic, quoting The Wire, scouring American blogs and importing policies and campaign tactics from the US.

But to the Americans the Brits are at best irrelevant and at worst irritating. Mr Brown gave Mr Obama a pen holder made of wood from the sister ship of HMS Resolute; the President gave the Prime Minister a set of DVDs that didn’t work. As Asia and South America gain in importance, it is clear that Uncle Sam no longer needs his European Mini-Me.

There was always an inequality between Britain and America, but the US used to respect the UK because it was reliable. With the release of al-Megrahi the bond of trust has been destroyed. The special relationship is over, but the real problem is that it is not at all clear what if anything will replace it. It is 45 years since the late US Secretary of State Dean Acheson said that “Great Britain has lost an empire and has not yet found a role”. As the balance of power shifts around the world, it is even farther from finding one now.

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