This vexatious question of intervention

If it has done nothing else, the Iraqi morass has soured the humanitarian dream espoused by Blair

Ten years ago, the West should have intervened to prevent a humanitarian crisis in Rwanda and failed to. One year ago, we did intervene in Iraq, with the results that we see today. In 1991, we didn't step in to save the Shia when they were being massacred after the first Iraq war. In 2003, we did and the Shia are rising up against us.

Of course, the occasions aren't the same. For a start, we didn't intervene this time in Iraq for humanitarian reasons. Tony Blair may have had this partly in mind in the conflation of causes that drove him to support the American invasion. He and President Bush may make much of removing a tyrant now that it's happened. But the more that comes out of Washington, in the 9/11 hearings and the intelligence investigation, the clearer it is that parts of the Bush administration planned regime change from almost the moment they took power and pursued it for reasons that had everything to do with their view of US interests in the Middle East and very little to do with Saddam's treatment of his own people.

Which is why, of course, so many Iraqis and Arabs remain so deeply suspicious of its motivations now in taking on Muqtada Sadr (the conspiracy theory is that the US doesn't want the handover to work so it can remain in charge longer, or at least wants to ensure Ahmed Chalabi and its own men stay in charge) and why many believe that progress cannot be achieved so long as the US is there as occupier.

You don't have to share the conspiracy theories to share that conclusion. Nor to see that the world cannot do what Colin Powell and Tony Blair now demand and move on without a resolution of the debate about the origins of this war. On your understanding of the motivations depends your view on where we go next.

On your understanding of the intentions also depends your view on how and where we should be intervening. If it has done nothing else, the Iraqi morass has soured the dream so eloquently espoused by the Prime Minister in the aftermath of 11 September of a world in which the Western powers committed their troops for humanitarian action across the globe.

We have not managed so well in Iraq - or, for that matter, Afghanistan, Kosovo, Bosnia or Rwanda - to encourage easy intervention just because of our military superiority on the battlefield. The aftermath is what matters.

That the public wants Western action in cases such as Rwanda or Bosnia or the 1991 assault on the Kurds is not in doubt. In the same way, they want to "do something" about famines and foreign civil wars when they see the pictures of the suffering they involve. And they are right. To have all this wealth, and all this might, and not use it for the wider benefit of those in need, on the grounds that it is none of our affair or that doing something is too complicated, is a moral disgrace.

But intention does become all important in this. What are you trying to achieve? What do the people concerned want? And what is your plan? The lack of these led to our failure to do anything about Srebrenica and Rwanda. The lack of them equally led to the situation in Iraq.

One of the worrying features of Tony Blair's recent pronouncements is the tendency, once again, to elide different aims in a single world view. The rules of intervention, the charter of the UN, the defence spending of Europe must all be radically revised, he suggests, to meet the new world of combating terror and stopping humanitarian disasters. But they are not the same thing.

Coping with terrorists demands police work and intelligence. Dealing with nuclear states requires diplomacy and pressure. Humanitarian intervention needs resources and co-operative effort. Assuming one thing (humanitarian benefit) will follow another (regime change to meet a perceived security threat) is what has got us into such trouble in Iraq.

The shame of Rwanda and other disasters considered UN failures is that we are further than ever from learning their lessons as a result of Iraq. The international community has been split. The UN has been greatly weakened and is further than ever from having the kind of resources and standing army that might enable it to act effectively. The regional bodies which might have acted in its stead have been deliberately excluded in the case of Iraq. The US-led international effort has produced a coalition of the willing rather than a willing coalition, countries that have seen it as a means to US favour, not a way to helping Iraq.

The lesson of Rwanda was that much might have been prevented if the international community had acted firmly at the beginning. The UN force was there and it could have been re-inforced if the organisation had troops on standby. Even more could have been achieved if we'd listened hard enough and got involved when the Hutus first started talk of ethnic cleansing. A clear need met by clearly defined action.

But that is not the lesson we learned in the Iraq war, and it doesn't seem to be the lesson we're learning there now.

a.hamilton@independent.co.uk