US press reports say that closed House and Senate hearings into the intelligence failures leading up to the attacks have found no single piece of information that would have prevented the attacks, had it been properly analysed. Without evidence of a single intelligence breakdown, the committees turn to investigation systemic failures of weaknesses in US intelligence agencies.

Police in Milan arrest nine people, mostly from north Africa, on charges of providing logistical support and false papers to members of al-Qaeda. Western intelligence agencies believe that Milan was major logistical base for al-Qaeda in Europe.

Spanish police arrest three men of Syrian origin suspected of being members of al-Qaeda. One suspect, Ghasoub al-Abrash Ghalyoun, was arrested in April and then released. Video tapes were seized at his home, some recorded during a trip to the US in 1997. Two of the tapes allegedly contain detailed footage of the World Trade Center from different angles and different distances that "goes beyond touristic curiosity", according to Spanish officials.

The House of Representatives approves a massive increase in intelligence gathering spending. The 2003 fiscal intelligence authorisation bill adds up to $35bn. The money goes to a number of agencies such as the CIA, the National Security Agency, Pentagon departments such as the satellite imaging section, and the Departments of State, Justice and Energy.

The House of Representative approves the creation of a massive Department of Homeland Security, designed to overhaul the way federal agencies deal with terrorism. The agency is responsible for guarding US borders, protecting potential targets such as the transportation system and overseeing the recovery from future attacks.