Adrian Hamilton: It was the war itself that was wrong

Putting Tony Blair in the dock before the Chilcot Committee was not the idea when the enquiry was set up. Just the opposite. Blame was very precisely not supposed to be the game. Yet in the dock he is today, having to explain away a tide of revelations about how Britain went to war and why it did so.

Quite right too. The invasion of Iraq was always a war Blair made very much his own. And to give him his due he has never pretended otherwise, preferring to declare it a project he personally always believed in rather than tamely followed in an effort to please the new Republican administration of President Bush.

If that invasion has gone down as a disaster to the country and our relations in the wider world, then Blair as the Prime Minister who agreed it, accelerated it through the Cabinet, persuaded the Commons to vote it through and tried to sell it hard to our allies around the globe, has to take the rap.

In concentrating on the former Prime Minister's culpability, however, my fear is that we will miss the central point, which is the decision to go to war itself. Forget all the questions of the legality of the invasion, the manner in which Blair sold it to Parliament and the lack of planning of its aftermath – serious charges although they are – the primary reason why Blair and all those who went along with him in Cabinet and out should be dragged in chains through the streets of Britain is that they took this country to war, without a thought to its alternatives or a regard to its consequences.

The truth is that Blair, Gordon Brown and all the colleagues who acceded, went to war because they thought it was easy. After all the experience of the first Gulf War, Sierra Leone and Kosovo, the choice seemed a simple one. You sent in the troops, they overwhelmed the opposition and a grateful civilian population threw flowers on the tanks and kisses on the soldiery.

And, let's face it, if that is what had happened, you wouldn't have heard all the sophistry and doubts that have come from the officials and ministers before Chilcot. None of them – except those few honourable exceptions who did resign on principle – would have said now that they had doubts at the time. They would have basked in the glory of a tyrant unseated and a country brought to peaceful democracy.

It didn't happen that way, of course, which is why we have the noxious sight of civil servant after civil servant now declaring that it was all against their better judgement and the Attorney General revealing how he had agonised until the last minute. Instead, we are seeing an even more pernicious reading of the affair as an argument between those who wanted to remove Saddam Hussein and those who didn't and which blames the failures thereafter as a lacking of planning rather than a fundamental mistake of judgement.

No. The division between the proponents of invasion and its opponents was not over whether Saddam Hussein should be dethroned. It was between those who believed war was a last resort that should only be undertaken when every other avenue had been exhausted, and those who looked on war as simply the most effective means of dealing with a perceived problem. For the former there had to be an overriding case in law and an urgent humanitarian necessity. For the latter, UN resolutions and Commons votes were just obstacles to be overcome on the way.

The interests of the Iraqi people in all this were just taken for granted, which was why there was never any proper planning for the post-war. Why bother with it when the aim was to unseat a tyrant and all the natives would be grateful for your doing it? We – and Britain is just as guilty in this as the Americans for all the efforts to slough off the blame on them – never understood the consequences for the same reason that we gave tacit approval for Saddam Hussein to invade Iran in 1980, failed to stop him invading Kuwait in 1991, didn't take advantage of the First Gulf War to depose him in 1992 and then went along with a decade of sanctions that starved his population, led to the deaths of tens of thousands of children and actually increased his hold on power.

It was why the intelligence services and the Foreign Office were so pathetically bereft of knowledge or understanding of the Iraq we invaded. Blair and Bush didn't invade Iraq to help its population, they did it to remove a regime and thereby – it was hoped – reshape the politics of the region.

Chilcot's inquiry reveals just the same mindset as Blair and Bush. It's being conducted from witnesses and documents coming solely from the government nexus. There is not one member of the committee that has any direct knowledge of the Arab world nor one witness called from the country whose interest we claimed we were promoting. It's as if the Iraqis don't exist, an amorphous mass without names or views whose interests we could, and did, decide for them.

It would be nice to think that we had learned at least some lessons from this debacle. The experience, and that of Afghanistan, has at least taught the politicians and public (most of whom knew it anyway) that war isn't the "cake- walk" that western predominance of technology and resources would imply, that invasion and occupation have consequences that require an understanding of people and place to predict.

But there is no real sign that the fundamental lesson, that war can only be an instrument of last resort tried when all else has failed and then only under the most precise circumstances, has been learned, as Britain desperately tries to earn favour with Washington by backing with forced enthusiasm every US move in Afghanistan. Gordon Brown talks of what he demands of the Afghans in the way of anti-corruption and deals with the Taliban for all the world as if he was a Victorian viceroy. And David Miliband lectures the Yemenis on what they must do to earn our aid. Chilcot certainly isn't going to teach our political class otherwise.

As for Blair, there really isn't any need for Chilcot to report at all. The former PM is now pinioned with responsibility for a disaster, a man guilty of a grotesque misjudgement that has left him discredited in his own country and in many parts abroad. One might wish it was for more. But for the moment it will suffice.

a.hamilton@independent.co.uk