John Rentoul: The really disturbing question about Iraq

Going in is not the issue now. Chilcot should be looking at how the occupation gave rise to such bloodshed

What is the Chilcot inquiry for? In the first four days none of its witnesses has said anything that was not already in the public domain. Not that you would have guessed from the high pitch and volume of media coverage. You probably have to be either a pro-Blair or an anti-war obsessive to recognise each piece of recycled information. But Sir Christopher Meyer, a former ambassador to Washington, happily if privately admitted after his session that he had said nothing that was not in his entertaining memoir, DC Confidential.

It seems surprising that Sir John and his colleagues had not identified the gaps in public knowledge, and called witnesses – or simply asked for papers – that they thought might be able to fill them. Perhaps they are coming to that bit. Perhaps this was just a bit of throat-clearing, a sort of "Previously, on Iraq War Conspiracy Theories...".

Where, then, are there gaps in our knowledge? Certainly not in the intelligence on Saddam Hussein's weapons of mass destruction. All four previous Iraq inquiries have focused on this subject. What the Chilcot inquiry ought to be about, instead, is the weakness of planning for, and the poor handling of, the post-invasion phase. Those of us that supported the invasion are unlikely to be persuaded that we are mistaken because of the flaws in the intelligence. What ought to disturb us is the terrible bloodshed that followed the invasion.

I still think the invasion was justified. But I can't pretend the post-war phase has been a success, even though it is finally getting better now. It is hard to say, as most Iraqis do, so far as can be judged, that it was "worth" the hardship to get rid of Saddam. No one can say that the deaths of perhaps 150,000 Iraqis were "worth it".

The question that is often asked is, "Would you have supported the invasion if you knew then what you know now?" In the case of the intelligence, it is meaningless, because, if we knew that Saddam had complied with UN disarmament resolutions, then there would have been no legal basis on which British forces could have taken part. But in relation to what happened next, it might be that, if the Americans knew then what they know now, Colin Powell's dictum, "You break it, you own it", might have prevailed over the hit-and-run mentality of the Pentagon.

That, then, would be a useful line of inquiry for Sir John and his colleagues. The problem is that post-war planning was overwhelmingly an American question, as it was overwhelmingly an American responsibility. It was Paul Wolfowitz, Deputy Secretary of Defense, who said 21 days before the invasion: "The notion that it will take several hundred thousand US troops to provide stability in post-Saddam Iraq [is] wildly off the mark." He said: "It's hard to conceive that it would take more forces to provide stability in post-Saddam Iraq than it would take to conduct a war itself."

That ought to be more of a reproach to Tony Blair than any flaws in the intelligence on Saddam's illegal weapons. Blair knew that the US plan for after the invasion consisted of little more than the momentum of victory. Yet his blithe optimism reinforced the arrogance of the Pentagon rather than balancing it.

Of course, even if Blair had feared the Americans had no plan and not enough troops, he would have thought it right to be part of the invasion, so that British forces, with their greater experience of nation-building, could influence post-war Iraq constructively. Blair shared the national belief that "we" were good at handling communal violence, while the Americans were only good for the shooting part. That turned out to be a hollow boast.

This is where Sir John and his colleagues could add to the sum of public knowledge. If the Americans failed to get a grip until the surge of early 2007, at least they did then; the British record turned out to be not so good. The Chilcot inquiry will in due course turn to the British rule of Basra and, in particular, the apparently shameful episode of the deal done by the British in late 2007 to hand over control to the local militia.

Sir John's work has been sketched out for him by my colleague, James Hanning, who in this newspaper last year quoted a senior British officer involved: "We have made some terrible mistakes in Iraq and it is only by talking about them that we will learn from them. Last autumn we made a mistake which was understandable but not excusable. A Shia prisoner, Ahmed al-Fartusi, said he could put a stop to the killings. We released 120 of their prisoners and withdrew out of town, but when we moved out, lawlessness took over. As 90 per cent of the attacks were against us, we thought if we moved out we would remove the source of the problem. But, actually, the Jaish al-Mahdi [the Mahdi army, known to British troops as the Jam] had been fighting us because we were the only obstacle to their total control." That was the thinking behind the remark, a year before, of General Sir Richard Dannatt, the head of the Army, that "our presence exacerbates the security problems".

With any luck, we will get to those questions in due course, although the quantity of material suggests that Sir John could take two years to complete his report rather than one. In the meantime, reporting of the inquiry will subside, with the occasional old fact reported as new if it can be stripped of caveats and sexed up to serve the anti-war story. Early next year, there will be a full-dress satellite-truck circus when Blair himself gives evidence – in which he will say nothing that he has not said many times before; he will say it well but he will be flayed alive by the press.

And the only lesson likely to be learned is one that we hardly need an inquiry to teach us: we will not be attempting anything like Iraq again for a long time.

John Rentoul blogs at www.independent.co.uk/eagleeye