Given the structure of the consortiums that operated the mines, it would be exceedingly difficult for Niger to transfer uranium to Iraq. Niger's uranium business consists of two mines, Somair and Cominak, which are run by French, Spanish, Japanese, German and Nigerian interests. If the government wanted to remove uranium from a mine, it would have to notify the consortium, which in turn is strictly monitored by the International Atomic Energy Agency. Moreover, because the two mines are closely regulated, quasi-governmental entities, selling uranium would require the approval of the minister of mines, the prime minister and probably the president. In short, there's simply too much oversight over too small an industry for a sale to have transpired.

(As for the actual memorandum, I never saw it. But news accounts have pointed out that the documents had glaring errors -- they were signed, for example, by officials who were no longer in government -- and were probably forged. And then there's the fact that Niger formally denied the charges.)

Before I left Niger, I briefed the ambassador on my findings, which were consistent with her own. I also shared my conclusions with members of her staff. In early March, I arrived in Washington and promptly provided a detailed briefing to the C.I.A. I later shared my conclusions with the State Department African Affairs Bureau. There was nothing secret or earth-shattering in my report, just as there was nothing secret about my trip.

Though I did not file a written report, there should be at least four documents in United States government archives confirming my mission. The documents should include the ambassador's report of my debriefing in Niamey, a separate report written by the embassy staff, a C.I.A. report summing up my trip, and a specific answer from the agency to the office of the vice president (this may have been delivered orally). While I have not seen any of these reports, I have spent enough time in government to know that this is standard operating procedure.

I thought the Niger matter was settled and went back to my life. (I did take part in the Iraq debate, arguing that a strict containment regime backed by the threat of force was preferable to an invasion.) In September 2002, however, Niger re-emerged. The British government published a ''white paper'' asserting that Saddam Hussein and his unconventional arms posed an immediate danger. As evidence, the report cited Iraq's attempts to purchase uranium from an African country.

Then, in January, President Bush, citing the British dossier, repeated the charges about Iraqi efforts to buy uranium from Africa.

The next day, I reminded a friend at the State Department of my trip and suggested that if the president had been referring to Niger, then his conclusion was not borne out by the facts as I understood them. He replied that perhaps the president was speaking about one of the other three African countries that produce uranium: Gabon, South Africa or Namibia. At the time, I accepted the explanation. I didn't know that in December, a month before the president's address, the State Department had published a fact sheet that mentioned the Niger case.