MPS and journalists were expecting another quiet summer week—one of the last before the end of the recess and beyond, the month-long travelling circus of conference season. Instead, they were summoned back to London to debate Syria, and the possibility of military action, in a special sitting of parliament. Fearful of losing the vote, last night the government retreated from its original plan to ask MPs for a mandate to intervene. Instead, the motion deplores the outrage of the gas attack in Ghutah and commits the government to returning to parliament for a second vote to approve any intervention.



Labour has since tabled an amendment setting out six conditions for any such deployment. At the time of writing, it looks like some Conservative MPs will back it. If unsuccessful, it is unclear whether the party will support the original government motion—possibly not, some say. That would be a double humiliation for David Cameron: defeated in the Commons over a motion that he had already been forced to water down.



His problem is that a majority of Labour MPs and a large minority (possible even a majority) of his Conservative MPs are highly sceptical about plans to intervene in Syria.



The reason is one-word-long: Iraq. As your correspondent argued five months ago, the 2003 war was beset with difficulties for which political leaders failed to prepare MPs and voters. The result is a much-underestimated national trauma that still haunts Britons. It turned them from interventionists to isolationists (is it any surprise that UKIP is leading the case against intervention in Syria?), and relegated foreign policy to a political afterthought:



"The experience has shocked Britons, turning a once gung-ho nation against intervention. According to YouGov, the proportion backing the war has slipped from 53% to 27% since 2003. The new majority is hardening: a recent ICM poll showed that more Britons think that “military interventions solve little, create enemies and generally do more harm than good” than reckon that “through its armed forces, Britain generally acts as a force for good in the world.”



Now, despite the horrors of Syria’s civil war, 66% of Britons oppose military action to overthrow Bashar al-Assad (compared to 39% opposed to intervention in Iraq in 2003). 60% even oppose military deployment purely tasked with protecting civilians. Britons are now distinctly isolationist by comparison with their European neighbours: YouGov shows that 10% fully back intervention in Syria (compared with 27% of Germans, 29% of French people and 30% of Swedes) and 24% completely oppose it (compared with 16% of Germans, 11% of French people and 8% of Swedes)."



Each of Britain’s main party leaders was himself conditioned by Iraq. Nick Clegg, the Liberal Democrat leader, has long decried the war along with his colleagues (the Lib Dems were the only main party to oppose it)—in 2010, in his first Prime Minister’s Questions appearance as deputy prime minister, he described it as “illegal”, a claim he later had to clarify. Ed Miliband was teaching at Harvard at the time of the invasion, but opposed the decision; a fact he touted widely during the 2010 Labour leadership campaign. David Cameron was an MP at the time of the 2003 vote—after much deliberation, he decided to back the invasion.

So all are at pains to distinguish any intervention in Syria from the invasion of Iraq. Mr Clegg went as far as to send his party members an email with the title: “This is not Iraq.” In it, he set out five reasons:

Chemical weapons have been used Britain has the support of international partners Proportionate military action would be legal Action would be deterrent in nature Britain has gone to the UN and there will be a vote in the House of Commons.

Mr Miliband raised similar points in his comments this morning—and the prime minister is expected to in his speech in the debate this afternoon. The problem is that none of them puts much water between the two conflicts:

Saddam Hussein had used chemical weapons in Iraq, too (at Halabja)—a point that both Britain and the US stressed in 2003. In the Iraq War, and the subsequent occupation, Britain fought alongside over 30 other countries. The invasion had the explicit or tacit support of most of the Gulf states. The matter of the legality of any action against the regime for using chemical weapons is more complicated than Mr Clegg suggests. As Dr Jonathan Eyal of RUSI argues, Syria is party to none of the relevant conventions banning the use chemical weapons; so from a legal perspective “cannot be held responsible for obligations it has never accepted.” Tony Blair used the deterrence argument in 2003. Furthermore, as Dr Eyal notes: “the fact that a sovereign state has violated international or bilateral obligation cannot be held to mean that other nations can take it upon themselves to enforce these obligations through the use of force.” Britain went to the UN in 2003—twice. It also put the Iraq intervention to a vote in the House of Commons—and won.

Many of the above objections were true of Britain's successful Kosovo intervention as well (for which Britain obtained no United Nations Security Council mandate, for example). There are also similarities with the Bosnian War, Britain’s failure to intervene in which continues to haunt older Tories, who - perhaps as a result - tend to support action in Syria.

And in two ways that Mr Clegg neglects to mention, the possible Syria intervention is indeed different from Iraq. The latter had the support of the majority of the British people and the majority of the House of Commons. The former appears not to.

None of which is to say that action on Syria is wrong—simply that Britain’s political leaders will never secure a popular mandate for action, or accurately describe the situation in Syria, by constantly talking about Iraq. The case for intervention in Syria should be judged on its own merits, not on the degree to which it does, or does not, resemble an intervention in a different country in different circumstances over a decade ago. That Iraq should feature in the Commons debate this afternoon is understandable. But it will be interesting to see whether, more than that, it dominates MPs and party leaders' speeches. If so, the debate will be poorer for it.