Matt Blaze on the New "Unpredictable" TSA Screening Measures
“Unpredictable” security as applied to air passenger screening means that sometimes (perhaps most of the time), certain checks that might detect terrorist activity are not applied to some or all passengers on any given flight. Passengers can’t predict or influence when or whether they are be subjected to any particular screening mechanism. And so, the strategy assumes, the would-be terrorist will be forced to prepare for every possible mechanism in the TSA’s arsenal, effectively narrowing his or her range of options enough to make any serious mischief infeasible.
But terrorist organizations—especially those employing suicide bombers—have very different goals and incentives from those of smugglers, fare beaters and tax cheats. Groups like Al Qaeda aim to cause widespread disruption and terror by whatever means they can, even at great cost to individual members. In particular, they are willing and able to sacrifice—martyr—the very lives of their solders in the service of that goal. The fate of any individual terrorist is irrelevant as long as the loss contributes to terror and disruption.
Paradoxically, the best terrorist strategy (as long as they have enough volunteers) under unpredictable screening may be to prepare a cadre of suicide bombers for the least rigorous screening to which they might be subjected, and not, as the strategy assumes, for the most rigorous. Sent on their way, each will either succeed at destroying a plane or be caught, but either outcome serves the terrorists’ objective.
The problem is that catching someone under a randomized strategy creates a terrible dilemma for the authorities. What do we do when we detect a bomb-wielding terrorist whose device was discovered through the enhanced, randomly applied screening procedure?
EDITED TO ADD (1/5): In this blog post, a reader of Andrew Sullivan’s blog argues that the terrorist didn’t care if he blew the plane up or not, that he went back to his seat instead of detonating the explosive in the toilet precisely because he wanted his fellow passengers to see his attempt—just in case it failed.