Intelligence - an issue at the heart of the US-UK invasion and occupation of Iraq - is the trump card for the prime minister and his inner circle. Other senior ministers - the foreign, home and defence secretaries and the chancellor - see weekly intelligence summaries (called 'Wizard' by Whitehall insiders) that are prepared by the Joint Intelligence Committee in the Cabinet Office. But the prime minister alone regularly sees the director general of the Security Service, MI5, and the chief (or C as he is still quaintly called) of the Secret Intelligence Service, MI6. So the prime minister and his closest advisers know more than anyone else (except the Queen, who sees all intelligence reports).
It is a position of power strengthened immeasurably by the supine approach of the vast majority of MPs when it comes to matters relating to security and intelligence. The parliamentary intelligence and security committee, chaired by former leader of the House Ann Taylor, meets only in private and has an all too cosy relationship with the agencies it is supposed to monitor. But privileged access to intelligence leads to dangers other than the unaccountable power knowledge provides.
Blair's determination to go to war against Iraq led to a more insidious and deeply sinister development - the distortion and manipulation of intelligence for political ends. It is a black art practised by totalitarian regimes and, more recently, in the US. Frustrated by unwelcome intelligence provided by the CIA (it had no evidence of official links between al-Qaeda and Saddam Hussein's regime, for example) and its distrust of Ahmad Chalabi's Iraqi National Congress, Donald Rumsfeld and his Pentagon cronies set up an alternative intelligence agency, the sinisterly-titled Office of Special Plans, to provide information to suit their hawkish agenda.
In Britain Blair and his closest advisers, Alastair Campbell especially, adopted a slightly more subtle approach. They took intelligence from MI6 and other sources and distorted it to suit their agenda. The result was a series of misleading dossiers designed to influence ministers, MPs and the general public.
With a phrase bearing all the hallmarks of a Campbell sound bite, Blair said in last September's dossier on Iraq's weapons of mass destruction (WMDs) that Saddam's 'military planning... allows for some of the WMDs to be ready within 45 minutes of an order to use them'. Blair made much of the discovery that Iraq was importing aluminium tubes - evidence, he claimed, of Saddam's nuclear weapons programme. Further evidence of Baghdad's nuclear aspirations, 10 Downing Street insisted, was provided by Iraq's attempt to procure uranium from Niger.
Experts from the UN's International Atomic Energy Agency exposed the documents on which these claims were made as forgeries. Britain's intelligence services subsequently admitted they were forged. The government has failed to put the record straight. Even Downing Street was embarrassed when contents of another dossier (handed out by Campbell to Westminster lobby journalists on the plane back from Camp David in February) were discovered to have been lifted from academic sources, including a PhD thesis by a US student. The dossier was put together by Downing Street with the help of the Coalition Information Centre, a body set up after the 11 September attacks to put the US-British case on the war against terrorism.
Already angry about the politicisation of the work of their cousins in the US, Britain's security and intelligence agencies were furious that the same thing was happening here - with shady corners of the government undermining their credibility.
One would have hoped this would all prove self-defeating. Alas, such is the appetite, not least in the media, for stories about 'intelligence' that journalists - including those from the once-revered New York Times and Washington Post - publish anything fed to them. Thus files taken from Iraqi intelligence and foreign ministries about George Galloway, alleged links between al-Qaeda and Baghdad and how the French were allegedly spying for the Iraqis on the US were all conveniently available for journalists, notably from the Telegraph, to peruse. Heaven knows what tittle-tattle and self-serving allegations would be found if the files of MI6 and MI5 were looted. There is a difference between that kind of thing and what the security and intelligence agencies actually tell the prime minister. (Or I certainly hope there is.)