WASHINGTON - Of all the government failures recounted by the Sept. 11 commission, one of the most important is perhaps the toughest to quantify and correct: a failure of imagination.
Despite abundant clues, analyses and scenarios of various kinds of attacks, no one, including Presidents Bill Clinton and George W. Bush, imagined that terrorists headquartered in a collapsed nation half a world away could mount such a devastating assault inside the United States, the commission said.
"The most important failure was one of imagination," the panel wrote in its summary. "We do not believe leaders understood the gravity of the threat."
Even Richard Clarke, the hard-driving former White House counterterrorism chief, wrote in a memo to his boss, National Security Adviser Condoleezza Rice, of an attack that could kill hundreds. He did not say thousands.
Panel co-chairman Lee H. Hamilton, a former Democratic congressman from Indiana, said, "We were often advised, during the course of the hearings, to read very imaginative writers, like Tom Clancy, and encouraged to think outside the box. And I think that's an important part of the counterterrorism effort."
Intelligence analysts and others offered intriguing clues in the years before 2001. The commission notes that suicide attacks were not new, and so "the leap to the use of other vehicles such as boats ... or planes is not far-fetched."
Officials didn't have to reach far for an early attempt at a crime strikingly similar to the Sept. 11 attacks, although the perpetrator was not a member of a terrorist group and the outcome not nearly as devastating.
A footnote in the commission report describes how in February 1974, a man named Samuel Byck attempted to commandeer a plane at Baltimore-Washington International Airport with the intention of "forcing the pilots to fly into Washington and crash into the White House to kill the president." Byck killed a co-pilot and an airport policeman before he was shot and killed by police while the aircraft was still on the tarmac.
As early as 1995, an accomplice of Ramzi Yousef in a foiled Manila airlines bombing plot told Philippines authorities that the two had discussed flying a plane into CIA headquarters.
That year, a prescient National Intelligence Estimate, one that gives the consensus view of the U.S. spy agencies, predicted future terrorist attacks against, even in, the United States. It warned that the White House, Capitol, Wall Street, power grids, sports arenas and civil aviation were vulnerable.
Subsequently, classified memos distributed to top policy-makers referred to Osama bin Laden's threats to use anti-aircraft missiles against American planes and his interest in acquiring biological or radiological weapons. A written briefing that Bush received on Aug. 6, 2001, was headlined, "Bin Laden Determined to Strike in the U.S."
Meanwhile, there were ominous warnings, the commission said. In 1998, "reports came in of a possible al-Qaida plan to hijack a plane," the panel states. A written briefing for Clinton that same year cited bin Laden's involvement in a hijack plot intended to free prisoners.
A threat report in September 1998, from a source who walked into an American consulate in East Asia, mentioned "a possible plot to fly an explosives-laden aircraft into a U.S. city." A month earlier, U.S. intelligence officials were informed that a group of Libyans hoped to crash a plane into the World Trade Center. Neither plot could be corroborated.
Just a year and a half before the Sept. 11 attacks, a Justice Department lawyer, writing of the legal implications of shooting down a U.S. aircraft, described in a 34-page analysis how a Boeing 747, used as a weapon, could destroy virtually any building in the world, the commission report states.
Yet all these hypotheses, scenarios and clues did not prod U.S. intelligence or policy-makers to pause and imagine the horrific potential of a group such as al-Qaida, according to the report. Intelligence assessments on terrorism sometimes contained only scattered mentions of al-Qaida and bin Laden.
Some of the clues and ideas were dismissed; others were not followed up. Federal Aviation Administration analysts in 1999 judged that a suicide hijacking would be unlikely, and the CIA did not write any assessments of such scenarios.
The North American Aerospace Defense Command started to develop an exercise to prevent a hijacked airliner from overseas crashing into the Pentagon, but "the idea was put aside in the early planning," in part because it was "too unrealistic," the report said.
Also, the commission states, "there were no complete portraits of [bin Laden's] strategy or of the extent of his organization's involvement in past terrorist attacks." Nor, before Sept. 11, had intelligence agencies "provided an authoritative depiction of ... the scale of the threat his organization posed to the United States." In fact, no national intelligence estimate was written on terrorism between 1997 and Sept. 11, 2001.