Since we relaunched Technology Review in mid-1998, we’ve taken as our mission telling you about the most important emerging technologies and their potential impact on our society, economy, culture and individual lives. Most of the time, fulfilling that mission means talking about the remarkable transformative power of new technologies. We live at a time when three simultaneous technology revolutions are under way-in information technology, biotechnology and, just over the horizon, nanotechnology. What’s more, those three revolutions will ultimately merge into a single force capable of changing almost everything about what it means to be human. As a result, writing and reporting for Technology Review is, most of the time, a pretty upbeat job.

Not always, though. One reason is that if our mission is to delineate the impact of emerging technologies, implicit in that mission is a responsibility to spell out the limits of those technologies-what they can’t do now and won’t be able to do in the future as far as we can see into it. We’re intrigued by the power of new technologies, but we’re not true believers in them. We aim to be just as hardheaded as we can. And the responsibility to be skeptical is never more important than when the stakes are high, when what’s at issue isn’t just economic or cultural change but the safety of our friends and family and neighbors. In the special report that forms the heart of this issue of Technology Review, “Technology vs. Terror,” we’ve tried to give you a clear picture of just what it is that technology can do to help make us safer-along with what it can’t do.

The essential message of this group of stories is conveyed in a memorable phrase from the essay by Edward Tenner. Tenner, a visiting researcher at Princeton and a widely published writer on technology, has twisted a clich to tell us that what September 11 really brought home was “the shock of the old.” Most of our military and intelligence agencies, he argues, were peering into the future, into a world where wars are virtual and the battlefield is cyberspace rather than deserts or mountains. All wrong, says Tenner-but not surprising. Every generation of technologists is in danger of forgetting the skills treasured by previous generations. Many young doctors, for instance, are wizards at interpreting batteries of high-tech diagnostic tests but aren’t very skilled at using a stethoscope. Against such a background, it seems logical that the FBI and the CIA were glued to their computer screens while the terrorists were commandeering airliners armed with box cutters.

What good is technology, then, at protecting us? The answer, as four feature articles show, is that technology is valuable in sensing terrorist attacks of all kinds and in making our built environment more resistant to destruction. Dave Talbot’s story, “Detecting Bioterrorism,” details efforts to create information networks to alert public-health authorities quickly to biological attacks. Indeed, a prototype version of this system was deployed at the inauguration of George W. Bush, where it detected, well, a flu outbreak.

The attacks of September 11 have also focused attention on the vulnerability of the large, complex systems on which our existence depends. In “Networking the Infrastructure,” Wade Roush shows that engineers are making systems such as the electric power grid harder to paralyze. Building on work that is already in motion to address difficulties in power delivery, power engineers will soon be able to give the power grid some of the capacity the Internet has to continue functioning even when part of the network has been taken down.

But if technology is becoming quite good at hardening major systems and alerting us when an attack has taken place, it still isn’t good at alerting us to attacks before they take place and helping us to prevent them. One reason is that the freedom and abundance of electronic communication make it virtually impossible to exploit as an early-warning system. As Kevin Hogan tells us in “Will Spyware Work?”, several classified projects aimed at collecting and deciphering e-mail and voice traffic failed miserably in giving police or intelligence agencies a heads up before September 11. The reason is simple: the software for making sense of the traffic can’t keep up with the volume. Don’t expect that to change anytime soon.

Nor will high-tech methods of identifying suspected terrorists be of much help in the immediate future. In “Recognizing the Enemy,” Alexandra Stikeman describes a universal system of automatic personal identification that might one day emerge from the nascent field of face recognition. But that dream-instantaneous recognition of individuals through video surveillance-remains a fantasy. Rendering it effective would require a shared database of photos, presupposing a level of cooperation among officials that doesn’t yet exist.

Fantasy isn’t what we need now. In the foreseeable future the job of prevention will continue to depend on what Edward Tenner calls the “tacit knowledge” possessed by police and intelligence officers. Another way of putting it is intuition based on experience. That’s what the Israeli airline El Al relies on. El Al, clearly an alluring target for terrorist groups throughout the Middle East, has an excellent safety record. A major reason is that the airline relies heavily on a combination of profiling and the intuition of well-trained security agents screening passengers at the gate. Pretty low tech. Then again, so are box cutters.