The case for the war against Iraq rested on fluctuating rationales. Those of us who opposed it watched with cynical fascination as the words of the statesmen groped for new reasons to suit the predicament they were in. George Bush and Tony Blair had embarked on a policy they could not reverse. At a certain stage, unless Saddam Hussein fled the scene, they were determined to have a war, and finally homed in on two justifications. These had different levels of explicitness. Both now stand in peril of being void. But the failure of one matters a lot more than the other. The failure to find any weapons of mass destruction is becoming an ever bigger deal. Neither 1,000 new US inspectors nor scores of interrogated Iraqi scientists are delivering the goods. It begins to be more possible to believe that most of the bad stuff was destroyed in the 1990s, and that Iraq was telling something like the truth when it claimed to have no weaponised chemical or biological material.  What we're learning more about than caches of weapons of mass destruction are the ferocious wars between politicians and intelligence agencies in the US and UK. For Mr Blair and the military establishment it remains an article of faith that the WMD exist. Blair says that any other outcome would imply a conspiracy by several agencies - the French and German as well as MI6 and the CIA - to lie to their political masters. Yet there is plenty of competing evidence that agencies were leaned on or sidelined by politicians in pursuit of answers that had become politically imperative.  The New Yorker has carried persuasive details of Donald Rumsfeld's creation of a private intelligence group to produce analyses both of the weapons of mass destruction issue and the al-Qaida connection that the CIA's professional scepticism restrained it from delivering. MI6 was seemingly complicit in a crude forgery of documents designed to show that Niger supplied Iraq with nuclear material. Downing Street was willing to stitch together an old academic paper and pretend it was a hot intelligence assessment.  All this happened in support of the WMD thesis, when it was up-front as the leading reason for the war. It was, after all, the only way of conferring legality. A war to enforce UN resolutions came to be defined as the essential link to what was internationally lawful. So the assertion of the presence of WMD in Iraq, even when they had not been discovered, continued as the lynchpin of the public case Bush and Blair made.  The failure of the weapons to turn up is, therefore, embarrassing. It should leave a permanent scar on the credibility of anything any government has to say about war and intelligence. It reminds us that when a war script has been written, the end is taken to justify any political means. But does it now do more than provide sniping material for the critics? Does it matter at the present conjunction of Iraqi events? Not as much as a failure of the second rationale, the ambition for political reform in Baghdad.  At the time, this was seldom made explicit. It filtered through Blair's passionate moralism about creating a decent society, but neither coalition partner talked easily about regime change. Pre-emptive war was a new enough concept, alarming in its implications. Naked intervention to impose a new politics on a sovereign state would have been an outrage too great to admit to. So, at any rate, it seemed to Washington and London. As it certainly did to their critics.  But again, circumstances have to alter judgment. Iraq is where it is. The war was won. Saddam has gone. The high ground, if semi-covert, case of the neo-conservative faction that drove Bush towards this war always was for a regime change that opened the way for Iraq to become some kind of magnetic pole of democracy in the Middle East.  I think that those of us who recoiled from the war on any grounds, and certainly on that one, now need to give its exponents the time to see what can be done. Those who once said the US must never go near Iraq should now urge the US to stay there, with every serious commitment it can muster.  Making the place safe for political freedom is a fantastically ambitious task. We keep being told that George Bush is not a simple man, but he talks about democracy as if it were a commodity ripe for handing over to the ready-made Mesopotamian heirs of Thomas Jefferson. The odds defined by culture and history make the liberal democracy of Iraq an improbable bet in anything less than a decade, if then.  I spent the weekend thinking about this in a different context, at a conference of a fledgling seminar called Ameurus. This is a group brought together by that most fertile animator of such projects, George Weidenfeld, to seek out the common ground between America, Europe and Russia. To hear the Russian speakers, keen democrats all, talk gloomily about human rights and elections and the rule of law was to be reminded how very difficult it is for democracy to penetrate the life and experience of people who are not used to it. Even a society educated in western traditions, knowledgeable in democratic theory, and unencumbered by religious allegiances that challenge it, has a long way to go before becoming a democracy in heart and mind.  In Iraq we've soon seen how unprepared the US was for the ambition it had. It didn't bring policemen, let alone nation-builders. It has not brought elementary order to the streets, and its   first cohort of proconsuls has already been deemed incompetent and sent home. Its clumsiness reveals a Pentagon apparatus better equipped to win a war than contribute to the peace. And don't forget: the builders of the democratic dream were, and are, in the Pentagon.  The message from the early calamities is to reinforce the need for an international approach. Perhaps Mr Blair can play a more effective role than he did before the war, and persuade Washington that what many nations will do for both the reconstruction and the political reform of Iraq is far more important than the effacing of the UN, on which those same Pentagon thinkers seem bent. Their political project has not the slightest hope of working as a unilateral act of imposition.  But they need to be committed. If they're serious about democracy, they'll have to pay for it: 75,000 troops and $20bn a year for several years to stabilise the peace, according to an estimate by the Council on Foreign Relations. They need to learn the subtlety required to preside over the emergence of genuine consultative mechanisms that might lead towards free politics in some sort of federal system. Above all they have to engage the world as leader not hegemon.  These would be hard concessions for the US. They would change the mindset of the Bush administration. But if their priority is as they state, we should now help to hold them to it.