Watching the live coverage of the House of Commons debate over the government’s motion to authorise an attack on Syria, I was reminded of the long shadow of the Iraq war. Speakers from all three major parties invoked Tony Blair’s ‘dodgy intelligence dossier’, and said they would not be stampeded into yet another conflict in the Middle East.

The loss of the vote late on Thursday evening was a huge setback to David Cameron, and was a useful lesson about the limits of power. Worse than the humiliation was the knowledge that when the American strike occurs, the British won’t be among those firing volleys of cruise missiles. This will be the first time for decades when the Brits won’t be in lockstep with their senior allies. Small wonder that David Cameron’s face was redder than usual when the votes were counted. Ed Milliband, the Labour Party leader, is now a hate figure in Whitehall for pulling the rug from under the Prime Minister’s feet.

As the war drums beat ever louder, I am reminded of a conversation I had in New York at the end of 2011 when I was there on my book tour. I met a young American diplomat at a friend’s flat in Manhattan where I was staying, and got interested when he mentioned that he had just returned from the Middle East where he had spent a year studying Arabic. We got on to the subject of Syria where the Arab Spring had just broken out, and there was much excitement about the possibility of the Assad dynasty being overthrown by a coalition of secular opposition groups.

Pundits never like being wrong, but I do recall suggesting that the Syrian government’s days were numbered. I based this optimistic assessment on the fact that Iran, Syria’s biggest backer, was itself being subjected to harsh sanctions, and with falling oil revenues, would be unable to bankroll its client state for very long. Also, the Syrian economy could not sustain months of civil war. At that point, jihadi elements had not entered the fray in any significant numbers, so I suppose I was indulging in wishful thinking.

The American disagreed, and was of the view that the conflict could drag on for years. In the event, he was absolutely right: even with the Americans poised to “fire across Assad’s bows” in Obama’s words, it seems that he is reluctant to do more than send a signal. And the message is more for Iran than for the Syrian leadership.

Obama wants to make it clear to the aayatollahs that he does not bluff, and just as the Syrian use of chemical weapons was a red line, so is uranium enrichment beyond a certain point.

There is a growing realisation, at least in the UK, that there are no good choices in Syria, just as there are no good guys and bad guys. In fact, Edward Luttwark wrote in the New York Times recently that it would be in the American interest to support whichever side was losing to drag on the conflict for as long as possible. He reasoned that an outright win for either side would be bad for the US, so rather than face either a jihadist victory or an Assad triumph, the Americans ought to play one off the other.

In the UK, both conservatives and leftists are against going to war, even if the military plays a limited role. This unusual consensus was reflected in the recent House of Commons debate when Labour, Tory and Lib-Dem members all united in defeating the government proposal. And this view is reflected across the country, with well over 50 per cent opposing the government’s desire to join the Americans, and less than a quarter of the population supporting it.

Apart from Iraq’s long shadow, the government is also saddled with the perception that it is acting on Washington’s bidding. Several MPs in the debate demanded to know what the hurry was, and why they had to act on a ‘timetable set elsewhere’.

The image of Tony Blair being labelled ‘America’s poodle’ is still etched in the public’s memory, and there is a clear sense that they no longer want to be dragged into America’s wars. Few today remember that when Saddam Hussein gassed thousands of his own Kurds as well as Iranian soldiers in the late 1980’s, the world didn't utter a word. When Iran demanded a UN debate, the Americans thwarted the initiative. But in those days Saddam Hussein was a friend of the West’s; indeed, his chemical weapons programme was only made possible by Western-supplied technology.

And while Bashar Al-Assad’s alleged use of chemical weapons that killed around 350 civilians is clearly repulsive, what are we to say about the slaughter of well over a thousand Egyptians by the army? Here, a coup is not a coup, but the first step towards a return to democracy; a dictatorship is a transitional government; and a massacre is an internal matter for Egypt.

It is this kind of hypocritical moral relativism that makes people suspicious of American motives in Syria. I have always viewed both Assads, father and son, as despotic thugs, and argued for Bashar’s swift removal from the scene when the uprising began in Syria in 2011. But the rapid transformation of the opposition into a largely jihadist/al Qaeda front gave me pause: how will we cope with a power vacuum in Syria that is filled by heavily armed and very dangerous extremists?

We should all be careful of what we wish for, and are now faced with a choice between two evils. Assad is bad enough, but what might follow him could be much worse. So when Saudi Arabia arms the jihadis, and America fires missiles at Damascus, we are left wondering about the nature of the alliance taking shape before our eyes: the US, Israel, Saudi Arabia and al Qaeda, all fighting shoulder to shoulder to topple Assad. Really strange bedfellows.