The Atta–Prague meeting

That Mohamed Atta, who flew American Airlines Flight 11 into the North Tower, met Ahmad Khalil Ibrahim Samir al-Ani, an officer of the Iraqi Intelligence Service working under diplomatic cover, in Prague on 9 April 2001 — and that the meeting established Iraqi state involvement in the September 11 attacks.

In October 2001 the Czech security service BIS passed on an account from a single informant, a source in the Arab community in Prague, who said he had seen al-Ani meeting an Arab man later identified from a photograph as Atta. Czech interior minister Stanislav Gross made the claim publicly. It was seized on immediately: Vice-President Dick Cheney described it on Meet the Press in December 2001 as 'pretty well confirmed', and the meeting became a fixture of the argument that Iraq had a hand in the attacks, promoted by Laurie Mylroie and repeated in newspaper reports built on Iraqi documents that were themselves later shown to be forgeries.

The Prague meeting mattered out of all proportion to its evidentiary weight, because it was concrete: a date, a city, two named men. It did work that the aluminium tubes and the yellowcake could not, connecting Iraq not to weapons but to the attacks themselves. Polling through 2002 and 2003 found large majorities of Americans believing Saddam Hussein was personally involved in September 11, a belief for which this claim was the principal public support. It was never retracted by the people who advanced it; it was simply left behind.