July 11, 2005

TAKE IT TO THEM BEFORE THEY GET TO YOU:

High-Tech Antiterror Tools: A Costly, Long-Range Goal (ERIC LIPTON and ANDREW C. REVKIN, 7/11/05, NY Times)

With the mass transit systems in Britain and the United States on high alert, the best available defense the governments can provide against a terrorist armed with a bomb is decidedly low-tech: vigilance with dogs, video cameras and security officers.

That limited arsenal has provoked calls for an accelerated campaign to develop high-tech tools like artificial noses that sniff out explosives or devices that can detect bombs through clothing.

"We need a crash program," said Senator Charles E. Schumer, a Democrat from New York.


Mr. Schumer's metaphor is more appropriate than he probably realizes: Why Just Detecting Hidden Explosives May Not Cut Deaths (SHARON BEGLEY, 7/08/05, Wall Street Journal)
Even under the best-case assumption of sensors that are perfect, covert and cheap enough to deploy at every city intersection or throughout plazas, early detection unambiguously lowers the casualty count only if the bomber fails to detonate. Ensuring that outcome probably requires ubiquitous deployment of perfect sharpshooters, says Prof. Kress.

Early detection can backfire because of the grisly fact that human beings act as human shields. "There is a trade-off between crowd size and crowd blocking," says Prof. Kaplan. A large, dense crowd puts more people in harm's way, but "the probability of being exposed to a bomb fragment declines exponentially with the size of the crowd." As a crowd flees, there are fewer people near the bomber to absorb the fragments (as when a soldier falls on a grenade) and more people, unshielded, farther away. Simple geometry shows that you can hit more people at a radius 20 feet from a bomber than you can five feet from him.

"If the first ring of unshielded people is at a greater radius, there are more of them, and more will be hit," says Prof. Kaplan.

The same effect occurs if people throw themselves to the ground. That minimizes each person's exposed area, but also at the expense of decreasing human shielding. For bombs with 500 or more fragments (in Israel, 1,000 is typical), "hit the deck" can raise rather than cut casualties. If scores of people fall from an average height of five feet eight inches to 1.5 feet, the scientists calculate, casualties could rise as high as 50 from 37.

"We are not suggesting that standoff detection has no use, but having the ability to detect explosives doesn't automatically make you safe," says Prof. Kaplan. Since the conclusions reflect a best-case scenario -- perfect sensors do not yet exist -- casualty reduction with real-world devices would be even less than the researchers calculate in their study, published online this week in Proceedings of the National Academy of Sciences.

The limits of technology are becoming apparent to those leading the war on terrorism. "Response [to detection of a suicide bomber] is a very difficult problem," says Todd Brethauer, science adviser to the U.S. Interagency Technical Support Working Group. "While there are tremendous efforts under way, don't expect a miracle near term."

Instead, pre-empting bombers before they reach their target and destroying explosives labs is likely to bring a greater payoff. Israel suffered 26 suicide attacks in 2003 and 15 in 2004, a decline it attributes in part to earlier interdictions.

Fathoming who suicide bombers are, what motivates them, and what can stop them has become particularly urgent now that such attacks in Iraq have reached unprecedented levels, with more than 200 this year. That has prompted concern that a generation of terrorists is learning skills it can bring to the U.S. and Europe. Science and experience show that last-minute defense is the wrong way to play this lethal game.


Note the Left has worked itself into a tizzy because Congress was cutting security funds for mass transit.

Posted by Orrin Judd at July 11, 2005 6:54 AM
Comments

No OJ: Rick is just rehashing the DNC talking points.

Incidenally, it was a facinating article. But the last graph was lame.

"Fathoming who suicide bombers are, what motivates them, and what can stop them has become particularly urgent now that such attacks in Iraq have reached unprecedented levels, with more than 200 this year."

No, the bombers are not the issue, thye have become mere tools. Their handlers are the real enemy.

"That has prompted concern that a generation of terrorists is learning skills it can bring to the U.S. and Europe."

Typical liberal meme. "We are training new terrorists in Iraq." Nonsense. We are killing them like flies. We need to kill more.

"This is the Perfect War. They want to die, and we want to kill them."
-Sgt. Major Henry Bergeron, 1st Marine Division


Posted by: Robert Schwartz at July 8, 2005 9:03 PM

In relation to this, as far as the tradeoff between security and convenience goes, the New York Daily News has an article today on reactions to the Port Authority's decision to cut off cellphone service in the Holland and Lincoln tunnels following last week's attacks in London, in order to eliminate the possibility of remote detonation of a bomb via a cellphone.

I believe cell service is also now possible on much of New York's subway system, so the need for suicide bombers is decreased if all you have to have is effective package droppers and someone who can operate a touchtone keypad. And of course, if your bomber opts to detonate the package on a train in one of the elevated portions of the system, or any other system in the country, there's nothing you can do about use of a cell-triggered device short of shutting down the phone towers completely.

Posted by: John at July 11, 2005 9:17 AM
« PELOSI VS CHURCHES: | Main | 99% PURE: »