have started hiding explosives in their underwear and body cavities, we have no alternative to these intrusive measures. This risk-based approach would be significantly more effective than current practice in dealing with the increasingly serious threat of airborne suicide bombers. It should be supplemented by beefed-up control of access to planes and their cargo holds on the tarmac at airports, to thwart those who would place bombs on board without getting on board as passengers. Fortunately, the Flight 253 bomber failed, due largely to his own incompetence. But unless we shift to a risk-based security policy, the next such attempt could well succeed. Robert Poole is director of transportation at Reason Foundation. He advised the White House and members of Congress on airport security issues following the September 11, 2001 attacks. An archive of his aviation security work is here . Robert Poole is Searle Freedom Trust Transportation Fellow and Director of Transportation Policy