From the National Journal:

Ten days after the September 11, 2001, terrorist attacks on the World Trade Center and the Pentagon, President Bush was told in a highly classified briefing that the U.S. intelligence community had no evidence linking the Iraqi regime of Saddam Hussein to the attacks and that there was scant credible evidence that Iraq had any significant collaborative ties with Al Qaeda, according to government records and current and former officials with firsthand knowledge of the matter.