” Even if the T.S.A. were somehow to make airports impregnable, this would simply divert terrorists to other, less heavily defended targets—shopping malls, movie theaters, churches, stadiums, museums. The terrorist’s goal isn’t to attack an airplane specifically; it’s to sow terror generally. “You spend billions of dollars on the airports and force the terrorists to spend an extra $30 on gas to drive to a hotel or casino and attack it,” Schneier says. “Congratulations!” “