The 9/11 commission's report is superb, but will it change anything?

The biggest puzzle about the 9/11 commission's report is why Thomas Kean, the panel's chairman, said at the start of his press conference this morning that the U.S. government's failure to stop the attack on the World Trade Center was, "above all, a failure of imagination."

It was a strange comment because the actual report—a superb, if somewhat dry, piece of work—says nothing of the sort. The failure was not one of imagination but rather of incentives. It turns out that many individuals, panels, and agencies had predicted an attack uncannily similar to what happened on Sept. 11, 2001. The problem was that nobody in a position of power felt compelled to do anything about it.

As early as 1995, Abdul Hakim Murad told Philippine authorities that he and Ramzi Yousef, who was arrested for his role in the 1993 bombing of the World Trade Center, had planned to fly an airplane into CIA headquarters. This wasn't dismissed as a crazy idea. The year before, a group of Algerians actually had hijacked a plane in France with the intention of crashing it into the Eiffel Tower.

In September 1998, a U.S. consulate in East Asia was warned about an impending al-Qaida plot to fly an explosives-laden airplane into an American city.

Around the same time, Richard Clarke, the White House counterterrorism chief, conducted an exercise in which terrorists commandeered a Learjet, loaded it with bombs, and flew it into a target in Washington, D.C. Clarke asked Pentagon officials what they could do to stop such a threat. They answered they could scramble jet fighters, but they would need authority from the president to shoot the plane down. The exercise went no further.

On Dec. 4, 1998, the President's Daily Brief by the CIA warned that "bin Laden and his allies are preparing for an attack in the US, including an aircraft hijacking" to compel the freeing of those responsible and imprisoned for the 1993 bombing of the World Trade Center.

The North American Aerospace Defense command also conducted an exercise to counter a terrorist attack involving smashing an airplane into a building (though the scenario assumed the plane would be coming from overseas).

Quite independently, in August 1999, the Federal Aviation Administration's intelligence branch warned of a possible "suicide hijacking operation" by Osama Bin Laden.

On May 1, 2001, the Federal Aviation Administration issued a circular to airliners, informing them of intelligence reports about a possible terrorist hijacking.

On June 22, 2001, the CIA notified its station chiefs about an al-Qaida plot to attack American cities with planes.