It will take a great deal more proof of Iraqi duplicity before I can support war

The manner and legitimacy of a military intervention may well completely alter its chances of success

People have been getting a bit overexcited. The unfavourable comments about Saddam's arms declaration coming from London and Washington do not yet amount to a case for war. Colin Powell has said that the dossier is "troublesome", our own Foreign Secretary argues that the declaration is not "complete, full and accurate" and Hans Blix, the UN's chief weapons inspector says that there are unanswered questions, an absence of supporting evidence and remaining gaps. So far, then, we do not have Blix without Straw.

In any case, even an acknowledged grossly misleading declaration by the Iraqis does not in itself constitute grounds for military action. Under the terms of Security Council resolution 1441, a false statement (which is what the US and Britain believe this is) would have to be followed by a failure to co-operate with the arms inspectors. It would certainly be taken as evidence of Iraqi bad intentions, but could be nullified by full compliance. The important date is the late January deadline when the UN inspectors and their counterparts in the International Atomic Energy Agency will give their view of Iraqi compliance. Nothing will happen before the Security Council has had a chance to examine their findings. Happy Christmas and a peaceful January at any rate.

And what then? Who knows? It may depend on what is found that shouldn't be and what is not found that should. Here there are, broadly, three possibilities. One, implicitly favoured by the ideologically anti-war camp, is that Saddam gave up nasty weapons a long time ago, some time after the Gulf War. Those that he still had were probably gradually rooted out by the UN weapons inspectors and – after their departure in 1998 – not replaced. He may be bad, runs this logic, but he ain't mad.

The second possibility, explicitly canvassed by US hawks and occasionally endorsed by the British Government, is that intelligence gleaned from defectors and from intelligence surveillance (not to be shared with the likes of you, me and the Russians) indicates a pretty active Iraqi horrible weapons programme. Such weapons have always been part of Saddam's plans for establishing hegemony in the area, goes the argument, and he hasn't changed. It's just the same old same old.

The third position is not really a contradiction of either of the above. It simply states that we do not really know either way. There are good reasons for believing that Saddam might have given up on, say, trying to make nukes, because he'd be squished the moment he paraded one on the end of a rocket. But on the other hand he has a history of over-reaching himself militarily, but only after giving his neighbours and citizens a thoroughly bad time.

For want of a better hole, I am with group three, but with a leg in group two. I can conceive of this regime maintaining a weapons programme, but I am not sure. And while I would like nothing better than to see UN troops liberate Baghdad to the sound of cheers and ululations, I require a proper casus belli before waving my little flag. A failure by Iraq to comply with the weapons inspectors would have to be read as evidence of the concealment of weapons of mass destruction. Or there might be the discovery of such weapons. Then the issue would go back to the Security Council.

Complication One. If there were a clear breach, and yet the Security Council failed to back action (let's say that the Russians or Syrians simply set their face against any effective response), would I be in favour of what the Foreign Secretary described yesterday as "The Kosovo Option" – whereby various states took it upon themselves to act without UN sanction? Menzies Campbell, the Liberal Democrats' splendid Foreign Affairs spokesperson, said this week that he wouldn't be. His argument was that Kosovo was different, more urgent and also (shifting his argument a little) less geopolitically risky.

Campbell's position is highly problematic. The dangers of not acting in the circumstances I've described seem as potentially great as those of going to war without a specific UN mandate. Saddam would be emboldened, as would any of the shadowy states who may, one day, find it in their interests to supply terrorists with the world's most dangerous weapons.

But here's the second complication. Campbell's real worry is that the world will believe that the US is set on war no matter what the material facts are. You will certainly find enough people to argue this case in any pub in Britain, and some US hawks have gone out of their way – for some strange psychological reason – to confirm this impression. If the US begins to set impossible standards for the inspectors, judging them by their success in, say, luring Iraqi scientists out of the country, and then acts without a UN resolution, the consequences could be dire. I have hardly met a single ordinary person in Britain in the past three months who doesn't express extreme scepticism about military action. I struggle to think of a parallel in recent times. If it's like that in London, one may easily imagine how things are in Amman.

The politics of Complication Two can alter one's calculation of risk. Broadly those who oppose war will point to the additional boiling resentment that such action would cause in Arab and Muslim countries. Those who favour action respond with what might be described as a reverse domino theory. The establishment of a democratic regime in Iraq (wave a wand and there it is, just like Afghanistan!) will act as a radical encouragement to democrats in other Middle Eastern nations. One by one, from Iran to Syria, to Saudi Arabia and the Palestinian entity, countries will open up to reformist pressures, and a new Arab polity will be created. Once this is done it will be easier to persuade or to cudgel Israel to make an agreement that will establish a proper Palestinian state.

This notion is not totally ludicrous. There are plenty of Iranians, for instance, who do see the logic in it. It has been a long-standing (and fully justified) complaint about the West that it has tolerated and even encouraged political backwardness in the Middle East, to the despair of the local populations. Indeed, this charge has now become a catch-all Arab alibi. Would it be so awful, then, if one such regime were toppled and replaced by a democratic one, pour encourager les autres?

Ideas, however, never float free, they always bear the imprint of their moment. The manner and legitimacy of an intervention may well completely alter its chances of success. A Saddamite regime, which is in clear breach of a UN resolution and which incurs the UN equivalent of a Papal bull against it, may be toppled to cheers from across the region. An Iraqi government that complies with UN requests and against which no further action is recommended, will be removed to the sound of anger and derision. And nowhere will this be greater than in the places where reform is most needed. In which case we would be better off working quietly and stolidly to encourage the democrats and reformers we say we care so much about.

David.Aaronovitch@btinternet.com