Judging by Bruce Schneier's review of Against Security: How We Go Wrong at Airports, Subways, and Other Sites of Ambiguous Danger, a new book by Harvey Molotch, this is a must-read:
The common thread in Against Security is that effective security comes less from the top down and more from the bottom up. Molotch's subtitle telegraphs this conclusion: "How We Go Wrong at Airports, Subways, and Other Sites of Ambiguous Danger." It's the word ambiguous that's important here. When we don't know what sort of threats we want to defend against, it makes sense to give the people closest to whatever is happening the authority and the flexibility to do what is necessary. In many of Molotch's anecdotes and examples, the authority figure—a subway train driver, a policeman—has to break existing rules to provide the security needed in a particular situation. Many security failures are exacerbated by a reflexive adherence to regulations.
Molotch is absolutely right to hone in on this kind of individual initiative and resilience as a critical source of true security. Current U.S. security policy is overly focused on specific threats. We defend individual buildings and monuments. We defend airplanes against certain terrorist tactics: shoe bombs, liquid bombs, underwear bombs. These measures have limited value because the number of potential terrorist tactics and targets is much greater than the ones we have recently observed. Does it really make sense to spend a gazillion dollars just to force terrorists to switch tactics? Or drive to a different target? In the face of modern society's ambiguous dangers, it is flexibility that makes security effective.
We get much more bang for our security dollar by not trying to guess what terrorists are going to do next. Investigation, intelligence, and emergency response are where we should be spending our money. That doesn't mean mass surveillance of everyone or the entrapment of incompetent terrorist wannabes; it means tracking down leads—the sort of thing that caught the 2006 U.K. liquid bombers. They chose their tactic specifically to evade established airport security at the time, but they were arrested in their London apartments well before they got to the airport on the strength of other kinds of intelligence.