The special relationship between Britain and America is about to be tested as both countries embark on inquiries that are set to blame each other for the intelligence failure over Iraq's weapons of mass destruction.
Britain is expected to draw first blood when the inquiry headed by the former cabinet secretary Lord Butler of Brockwell, reports in the next few months. George Bush - quite deliberately - will wait until after this year's presidential election before his inquiry reports.
In the meantime, America's intelligence community will brief both countries' media to publicise flaws in Britain's intelligence gatheringto pre-empt Lord Butler's findings.
Last year's transatlantic intelligence tiff over MI6's claim that Saddam had cultivated contacts with Niger to acquire uranium may be a taste of things to come. It forced Mr Bush into an embarrassing climbdown and the admission that the US had been over- reliant on British intelligence. The fall-out left MI6 and CIA on bad terms.
But the central issue will be whose intelligence formed the basis of the flawed assessment of Saddam's secret weapons. For once, Britain's reliance on American intelligence might turn out to be a blessing in disguise. If Mr Blair can show that the erroneous war prospectus of September 2002 was based on American intelligence failures he may escape some of the political damage from his own inquiry. The question will then become: "Why was British intelligence so dependent on America?"
Of even greater concern may be the revelation that there was a serious dearth of firm intelligence in the first place and the way the same material was recycled, making appearances in British, American, Russian and French assessments.
Research published in The Scotsman this week shows just how easy it is to trace these precious pieces of intelligence. The newspaper's analysis of published American intelligence reveals a striking similarity to claims in the British Government's prospectus for war. Perhaps the most incriminating aspect is the source of the intelligence claims made by the Government about Iraq's use of unmanned aircraft, or drones. The September dossier asserted: "We know from intelligence that Iraq has attempted to modify the L-29 jet trainer to allow it to become an unmanned aerial vehicle (UAV) which is potentially capable of delivering chemical and biological agents."
Two years earlier, a document published on the CIA website used a similar form of words when it stated: "Iraq has continued to work on its unmanned aerial vehicle (UAV) programme, which involves converting L-29 jet trainer aircraft originally acquired from Eastern Europe. These ... are believed to be intended for delivery of chemical or biological agent."
The suggestion that British bases in Cyprus were within range of Saddam's missiles also looks familiar. This appears to have been based on a US defence report released a year earlier by William Cohen, who was US Defence Secretary under Bill Clinton.
Using the same concentric rings featured in the September dossier, the CIA intelligence graphic clearly shows Cyprus to be in range of Saddam's Al Hussein missile.
The Scotsman also recalls the No 10 dossier stating: "Intelligence shows that other important procurement activity since 1998 included attempts to purchase one large filament-winding machine, which could be used to manufacture carbon fibre gas centrifuge rotors." This information was culled from page three of the United NationsInternational Atomic Energy Agency report in 2000.
Further questions were raised in America yesterday after publication of a Pentagon Defence Intelligence Agency report from September 2002, which said: "There is no reliable information on whether Iraq is producing or stockpiling chemical weapons."Reuse content