Lord Butler cleared Tony Blair of any deliberate attempt to "mislead" the country in the run-up to the war in Iraq. But the body of his report tells a different story. Lord Hutton's inquiry last year, revealed the extent to which Downing Street hardened up the case against Saddam Hussein in its September 2002 dossier on alleged weapons of mass destruction that prepared the way for war.
Lord Butler's report shows the gap between Mr Blair's conclusions and what the intelligence services were saying was even bigger than emerged during the Hutton inquiry.
He recognised this gap when he said the language of the dossier was "fuller and firmer" than was the actual case.
Iraq under Saddam was a notoriously difficult country for western intelligence services and the Britain's Secret Intelligence Service, MI6, was no exception. It regularly admitted as much in the memos, known as CX files, sent round to what it describes as its "customers" in Whitehall containing bits of information from round the world, some of it important, most of it trivial.
Britain had good intelligence on all Iraq's neighbours but what was going on inside Baghdad remained, as one minister admitted at the time, "a black hole."
The doubts and caveats about intelligence disappeared as the dossier was compiled.
Lord Butler chronicles this with a clarity rare in a government report. He concludes that the intelligence was "thin," "unclear" and "uncertain."
The most damning passage is an admission by the intelligence service that it had received almost no new intelligence from within Iraq about WMD since 1998.
That sits uneasily with Mr Blair's claim at the time that Saddam had continued to pursue his ambitions to develop WMD and that the threat posed was imminent and serious.
The reality was, says the report, that "there was no recent intelligence that would itself have given rise to a conclusion that Iraq was of more immediate concern than the activities of some other countries."
In a telling phrase, Lord Butler said the intelligence was stretched by the government to the "outer limits."
His report included material on:
Sins of omission
The government announced in the spring of 2002 that it would produce a dossier.
Public scepticism in Britain was high and the dossier was designed to try to sway opinion. The dossier was a combination of Downing Street and the joint intelligence committee, the body of senior intelligence officials that sifts through the CX files to produce general reports that are normally only seen by "customers." In this case the report was to be made public.
Lord Butler noted the benefit to the government in making clear that it was the JIC rather than Downing Street that had ownership of the document: "The advantage to the government of associating the JIC's name with the dossier was the badge of objectivity that it brought with it and the credibility which this would give to the document."
JIC assessments, which its "customers," mainly Foreign Office diplomats, receive every few weeks contain many caveats about reliability and lack of information. When the dossier was published by Downing Street on September 21, such caveats were missing.
A JIC draft assessment, less than a fortnight earlier on September 9, said bluntly: "We have little intelligence on CBW (chemical, biological weapons) doctrine and know little about Iraq's CBW work since late 1998." This was missing from the final dossier, which instead contained a much softer version: that while intelligence "rarely offers a complete account of activities," taken together with what is already known from other sources, "this intelligence builds our understanding of Iraq's capabilities and adds significantly to the analysis already in the public domain."
Lord Butler concluded that it was a "serious weakness" not to have included normal JIC warnings.
Accuracy of the dossier
The JIC assessment of the threat posed by Saddam from chemical and biological weapons was heavily caveated. Its assessment on September 9 was that "production of sarin and VX would be heavily dependent on hidden stocks of precursors."
When the dossier was produced there was no mention of this important condition. Nor did the dossier refer to the JIC admission that there was little evidence about locations for producing such chemical and biological agents. The JIC assessment on September 9 said the former Habbaniyah chemical weapons site could provide a base for producing ricin, "although there is no evidence that Iraq is currently doing so." There is a further contrast, though oddly Lord Butler does not refer to it.
The JIC assessment on September 9 quoted by Lord Butler says intelligence indicates that "Saddam has identified Bahrain, Jordan Qatar, Israel, Kuwait as targets.
Turkey could also be at risk." But in the dossier this becomes Iraq possesses Scud ballistic missiles "capable of reaching Cyprus, eastern Turkey, Tehran and Israel." The inclusion of Cyprus, and its elevation to top of the list, was because of the need to demonstrate a threat to Britain, which has an RAF base on Cyprus.
There are many other such contrasts between the JIC assessment and the final dossier. Downing Street was keen to emphasise that Iraq could pose a nuclear threat and this was reflected in the dossier as Iraq "continues to work on developing nuclear weapons." Missing, also, was the JIC assessment that "we have an unclear picture of the current status of Iraq's nuclear programme."
The dossier claimed that Iraq was seeking aluminium tubes for use in its nuclear programme. Lord Butler found "overwhelmingly" that the evidence pointed to these being sought for use for rockets rather than the centrifuges needed to produce weapons-grade uranium. He concludes: "But in transferring its judgments to the dossier, the JIC omitted the important information about the need for substantial re-engineering of the aluminium tubes to make them suitable for use as gas centrifuge rotors. This omission had the effect of materially strengthening the impression that they may have been intended for a gas centrifuge and hence for a nuclear programme."
The 45-minute claim
The most spectacularly misleading of all the claims in the dossier was the failure of Downing Street to make clear that the relevance of the warning that Saddam could deploy chemical and biological weapons within 45 minutes. The positioning of the claim meant it could be read that Saddam was capable of launching strategic missiles armed with chemical or biological or nuclear weapons within 45 minutes at targets such as Israel or Cyprus.
Lord Butler was critical of what he charitably refers to as an ambiguity but said he had no evidence this was a deliberate distortion. The Hutton inquiry showed it referred only to battlefield weapons.
Lord Butler makes it clear that the 45-minute claim was based on flaky evidence and praised Brian Jones, from the Ministry of Defence intelligence section, for expressing scepticism as the time.
The source of the 45-minute claim has not yet been identified. Lord Butler said after publication of his report that the information was not even secondhand but third hand, and that the middle man in this trio had since been discredited.
About 90%, and often much higher, of the intelligence sent to "customers" is from the US intelligence agencies rather than British and is based on listening posts rather than human intelligence. In the case of Iraq, Britain was dependent on the US for what limited information was available but it also had human sources of its own.
These sources provided the bulk of the intelligence for the more contentious parts of the dossier. Lord Butler's report reveals the extent to which these resources were flaky: one of them was last July deemed to be unreliable and sacked.
Validation of sources
The inquiry finds attempts to explain why so many of the sources used by British intelligence on Iraq proved, after the war, to have been flaky. A particularly sharp conclusion was that in the haste to gather more intelligence to use in the September 2002 dossier, agents were relied upon who had not been properly vetted. Agents were asked to provide information that went beyond their direct knowledge, leading to speculative dispatches. Under pressure, agents drew on untried sub-sources and sub-sub-sources, several of which have since been found to have provided inaccurate information.
Lord Butler is critical of the language in the dossier, which he says "may have left with readers the impression that there was fuller and firmer intelligence behind the judgements than was the case." He also said: "We detected a tendency for assessments to be coloured by over-reaction to previous errors." He added: "As a result, there was a risk of over-cautious or worst case estimates, shorn of their caveats, becoming the 'prevailing wisdom'."