The FBI has launched a new counterterrorism operation designed to locate and disrupt "sleeper cells" of foreign terrorists before they can launch another major attack in the U.S., officials say.
Called Operation Tripwire, the program began quietly this summer and provides each of the bureau's 56 field offices with a standardized way to identify travel, financial transactions, equipment purchases and other factors that could be precursors to terrorism.
"We have taken the tragedy of 9/11, learned lessons from it and developed a strategic plan to prevent another incident like that," said one FBI official in Washington.
Added another senior counterterrorism official: "Just because we haven't had an attack in the U.S. in the last two years doesn't mean we have no threat."
The comment reflects a somber realization among such officials that the absence of major terrorist incidents in the U.S. since Sept. 11, 2001, is a consequence of aggressive law enforcement and, to some extent, luck.
Indeed, even as the FBI has taken credit for disrupting about 40 planned terrorist incidents in the last two years, both high-level officials and street agents acknowledge that they cannot ensure continued quiet.
Since September 2001, they note, Al Qaeda has been linked to two dozen terrorist attacks overseas. More ominously, some longtime counterterrorism officials theorize that the network has not struck the U.S. since the downing of the twin towers only because it is determined to unleash another catastrophic event, rather than a string of smaller attacks.
With that grim possibility as a backdrop, FBI officials say they conceived Operation Tripwire to provide an improved and standardized method for counterterrorism agents across the U.S. to use in detecting threats.
Just as the Defense Department has long employed an "indications and warnings" system to prevent attacks, the new FBI operation would provide a model for considering disparate factors in predicting incidents, officials say.
"This is designed to be a fail-safe system," said the senior FBI official in Washington. "If a major attacker comes to the U.S., the challenge is: How do you find them, how do you stop them?"
An early example of the tripwire approach occurred not long after the 2001 attacks when FBI agents began monitoring the rental of crop-duster aircraft nationwide.
The action was prompted by reports that the operational leader of the Sept. 11 plot, Mohammed Atta, had made inquiries about renting a crop-duster in Florida months before the attacks on New York City and the Pentagon.
Although those reports were never substantiated by the FBI, they did raise concern among counterterrorism officials that such aircraft could be used by a terrorist to unleash chemical or biological weapons anywhere in the country.
Under the new program, the FBI is building upon the experience of the crop-duster monitoring to examine other transactions that individually might be suspicious and, in the aggregate, could prove significant. Those possible clues range from unusual cargo movements at ports to missing stock at chemical plants, from overseas financial transactions to local apartments where tenants come and go.
"Tripwire provides an opportunity for the FBI to further our primary mission by giving indicators of future terrorist attacks.... It's another tool in our toolbox," said FBI agent Jan Caldwell in San Diego.
In Las Vegas, the bureau's Albert J. Pisterzi added that the program standardizes the indicators of potential terrorism and centralizes the intelligence collected throughout the world so it can be analyzed and distributed by the Strategic Information and Operations Center at FBI headquarters.
"It's a more coordinated effort worldwide to attack terrorism," said Pisterzi, who supervises the Joint Terrorism Task Force in Las Vegas. "And the greater coordination has proven valuable to those of us in the field."