The Independent on Sunday had learned that a senior American figure had gone to the west African state of Niger to investigate a claim that Saddam Hussein had tried to buy uranium for nuclear weapons there - and had found it untrue.
Britain had included the assertion in its September 2002 dossier on Iraq's alleged weapons of mass destruction. Even though it had been sceptically received, the claim was repeated in January 2003 by President George Bush in his annual State of the Union address. In that symbolic, televised speech, delivered before both houses of Congress, Mr Bush told the American public: "The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa."
With war in Iraq imminent, and so many other charges being flung against Saddam, this one did not attract much scrutiny. But six months later, with Baghdad in coalition hands and Mr Bush having declared major combat operations over, the questions about the failure to find WMD were proliferating.The IoS was told by a source that someone in the US knew the truth about the "Niger uranium" claim. The source felt honour-bound not to reveal his name, but said we could easily find out in Washington. He was right: to those familiar with the issue, Joe Wilson's mission was common knowledge.
The former diplomat, who once served in Niger, had travelled there in 2002 at the request of the CIA to investigate the claim. During his eight-day visit he satisfied himself unequivocally that it was untrue that Iraq had been seeking the uranium, and that documents purporting to show a deal must be fakes. When the International Atomic Energy Agency (IAEA) finally had the opportunity to look at the documents itself, it concluded they were forgeries. Last week the Italian newspaper La Repubblica reported that they had been created by low-level agents of Sisme, the Italian intelligence service, which was trying to curry favour with the White House by supporting its WMD campaign.
In June 2003 Mr Wilson told the IoS it was all but impossible that British intelligence had not also been told of the findings of his mission. When the uranium story appeared in Britain's WMD dossier, he even told the CIA to alert their British counterparts to their error. He outlined his belief that the Bush administration had twisted the intelligence to make a case for war against Iraq and had chosen to ignore his report.
Mr Wilson asked that the IoS identify him only as a "retired ambassador to Africa who went to Niger". The reason for this became clear the following weekend, when, in a signed piece in The New York Times, he wrote a full account of his investigation entitled "What I didn't find in Africa". In it he wrote: "I have little choice but to conclude that some of the intelligence related to Iraq's nuclear weapons programme was twisted to exaggerate the Iraqi threat." The impact of this piece was huge, and it forced the White House on to the back foot. The then CIA director, George Tenet had to apologise over the claim in the State of the Union address, saying: "These 16 words should never have been included in the text written for the President."
Britain continued to insist, however, that it had separate intelligence that validated the claim. The Foreign Office hinted that it was connected to the visit of an "Iraqi delegation" to Niger in 1999, but when the IoS interviewed Wissam al-Zahawie, the only Iraqi diplomat to go there that year, he said he had been investigated and cleared by both the UN and the US.
Mr Wilson's article, however, made him a target for the White House. Little more than a week after it appeared, the conservative columnist Bob Novak reported that the ambassador's wife, Valerie Plame, was a covert CIA operative, and that she had suggested sending her husband to Niger. He said he had been given the information by "two senior administration officials".
Mr Wilson long suspected the attempt to smear him went to the very heart of the administration. In a subsequent memoir, The Politics of Truth, subtitled "Inside the lies that led to war and betrayed my wife's CIA identity", he wrote: "I am told ... that the office of the Vice-President - either the Vice-President himself or more likely his chief of staff, Lewis 'Scooter' Libby - chaired a meeting at which a decision was made to do a work-up on me." And Mr Wilson told the IoS he believed it was very unlikely that Dick Cheney was not aware of what was happening. "If he did not know about it, he should be saying so."