In the case of the September 11 attacks, as journalists soon realized, the terrorists’ methods were surprisingly low tech. In fact, the technologies involved had been established for a generation-30 years, plus or minus five.
While the building design was tested to withstand a hit from a 707 jet, the Boeing 747, with its immense fuel loads, was already in service by 1969. The terrorists also apparently needed no sophisticated knowledge of automatic pilots and global positioning satellites. They had simply, and all too well, learned the classic principles of flying.
The immediate goal of the hijackers was also a 1970s concept: stunning the world with photogenic violence, as at the 1972 Munich Olympics. Thanks to satellite feeds, cheap color televisions and the Internet, these images could now have a more rapid and vivid impact, but the principle was old hat. So was the idea, dating at least from the time of the Ho Chi Minh sandal-carved by resourceful Viet Cong soldiers from rubber tire segments-that the improvised technologies of poor countries and peoples might humiliate the West. The terrorists understood all too well this neglected feature of technology: with enough determination, practice and time, mature and even seemingly outdated tactics and devices can be reborn.
What can halt future attacks? The events showed the limits of communications monitoring and satellite surveillance. The question remains whether more ambitious programs like the FBI’s troubled Carnivore e-mail-sniffing technology or facial recognition software will unearth new data on terrorist activity, or simply compound the familiar problem of information overload and produce an illusion of control. The frequent false alarms from even the simplest home security systems are already a plague for the police.
We obviously need to think more about protection from both newer and older forms of attack. One common feature of both is reliance on personal networks. The terrorist cells’ apparent methods of recruiting from the same regions, clans and families, and moving frequently from base to base, make them difficult to infiltrate conventionally-but they also reveal patterns to experienced analysts, making more targeted technical surveillance possible. We don’t need another decimal place of accuracy from computational social-science studies but a better intuitive understanding of the terrorists and their civilian neighbors. At the same time, the tacit knowledge possessed by the most effective police officers and detectives deserves more respect. One of our great challenges will be to formalize and teach these elusive skills to security screeners at airports and elsewhere.