Any inquiry must examine the role of the politicians, not just the spies

The crude political reality is that the dossier's effect on public opinion was outweighed by the damage to public trust

Suggestions that the announcements from Washington and London on inquiries into the intelligence on Iraq's supposed weapons of mass destruction have been carefully co-ordinated are somewhat exaggerated. Tony Blair and George Bush have certainly spoken since David Kay, the former US chief weapons inspector, said last week that Iraq had no stockpiles of biological or chemical weapons and only the most rudimentary nuclear weapons programme.

The Prime Minister, moreover, made it pretty clear to Washington that he needed to get through the Hutton inquiry before contemplating anything wider. What Number 10 does not seem to have been ready for was the speed with which the White House let it be known at the weekend that it was ready for an intelligence inquiry. Hence the rapid scramble in London yesterday to establish the composition, timetable and remit for the British inquiry.

In terms of long-term lessons, as opposed to short-term political cost-benefit for the Government, the remit, and how the inquiry interprets it, is especially important. The Government is certainly entitled to say that Lord Hutton has cleared it of falsifying the September dossier, and that this issue need not be revisited. And on the question of whether the Government did sex-up the dossier to make the best case for war that the intelligence assessments would bear - which even Lord Hutton allows is arguable - the Government always had a defence. Which was that the Joint Intelligence Committee, including the heads of the agencies themselves, signed the document off. That's why political gravity is dragging the focus on to whether the intelligence agencies did their job properly in the first place.

That is no reason for the new inquiry to exempt the political process from its deliberations. Of course there is a strong case for going back to square one and asking how reliable was the original intelligence which pointed to Saddam's having weapons of mass destruction. It is possible that intelligence was at fault before it was ever considered for inclusion in any dossier, in other words well before it fell into the hands of politicians. Possibly, it related to small amounts of material subsequently smuggled into Syria. On the other hand, some of it - perhaps even the 45-minute claim - may have been planted by figures in the regime in order to frighten the invading forces. Maybe Saddam skilfully maintained the fiction that he had a WMD capability in order to frighten his numerous enemies, most notably the Iranians. And so on. It makes sense for the inquiry to consider all these possibilities - from the notion that there is still a weapons programme out there to be found to the idea that there is nothing.

But the inquiry will hardly be doing its job if it doesn't also consider other questions - not conclusively laid to rest by Hutton - on how the intelligence was brought into the public domain, how this affected the way it was presented and whether the existence of the dossier served the best interests of the intelligence services as well as the country at large. On Sunday, Mr Kay told Fox News that mistakes were made as analysts prepared intelligence for their political masters, adding: "There are caveats that clearly dropped out as you moved higher up and people read the headline summaries."

Whether that's true or not, that is a pertinent subject for inquiry. You don't have to believe that the Government actually falsified the intelligence (which it didn't) or deny that Tony Blair was convinced that it pointed to Saddam having a biological, chemical and nuclear capability (which it is overwhelmingly probable he was) to question whether it was sensible to use the intelligence material as a means of making the public case for war, or -"sub-consciously" or not - that that purpose influenced the JIC chairman John Scarlett.

With the luxury of hindsight, it is easy to question whether it was sensible for the Government to produce the dossier at all. On the one hand, there was indeed a strident clamour for "the evidence" to justify war. I can remember one senior official at the time musing that it was better for London than Washington to produce such a dossier because it would be subject to less critical media scrutiny here than in the US. But the real reason that it was left up to London was probably that the issue of evidence was more radioactive here than in Washington. The British government was much more interested in UN and legal ratification than the US administration; and that required a case built on security rather than - say - Saddam's systematic human rights' abuses.

Once the dossier was agreed as a strategy, all the pressures - vividly laid bare in the succession of Hutton-revealed e-mails which flew around Downing Street - were to make it as persuasive as possible. And yet there may have been an alternative. Which was for the Prime Minister to say bluntly that the intelligence, though suggestive, was very far from conclusive; that there were real questions - which there certainly were - about why Saddam had produced no records to show the destruction of carefully quantified lethal material unaccounted for when the inspectors had left Iraq last time around; that it was an open question whether he still harboured such weapons; but that as Prime Minister he did not believe, given Saddam's record, that it could be left to chance.

The crude political reality is that the effect on public opinion of the dossier was outweighed by the damage it has subsequently caused to public trust in the Government. Which is why it may well be time for some sober and public reflection on the part of the Prime Minister, perhaps as early as today or tomorrow. For example, while Sir Richard Dearlove, the head of MI6 told the Hutton inquiry that in hindsight the 45-minute claim might have been given undue prominence, no minister, as far as I know, has yet echoed the point.

This is not necessarily the same as saying that it was wrong to go to war. But it still matters. The use and handling of intelligence, particularly in the entirely innovative circumstances of its being made public, goes to the heart of credibility of government - and of the intelligence services themselves. Sir Rodric Braithwaite, a former chair of the JIC, used a recent Chatham House speech to quote two remarks by one of his predecessors Sir Percy Cradock. In his book on the JIC, Sir Percy pointed out, first, that "we must accept that in the last resort intelligence is an attempt to know the unknowable and we must scale down our expectations accordingly;" and secondly that the risk that government imposes on the agencies is that "the analysts become courtiers" instead of reporting "unpalatable" findings without fear or favour.

Nothing matters more than trust in a government which commits troops to war. Which is why the new inquiry will be doing the national interest no favours if it simply asks whether the spies alone are to blame.

d.macintyre@independent.co.uk