The sudden change in air security rules imposed last week in response to the British terror plot has raised new questions for the Department of Homeland Security. Among them, why aren't systems for detecting liquid explosives already deployed or at least well along in development? And why isn't more being done to profile passengers, looking for suspicious behavior?
At airports nationwide Monday, all passengers were ordered to remove their shoes — a rule that had been enforced inconsistently even though the danger was discovered, in Richard Reid's shoes, nearly five years ago.
But members of the 9-11 commission say the government has done too little to stay a step ahead of the threat.
Especially, they say, in not accelerating research on detecting liquid explosives.
"It's appalling to us that five years after 9-11, you do not have detection devices for all kinds of explosives," says Lee Hamilton, 9-11 commission co-chairman.
And they say the government has been slow to install machines that sniff passengers for traces of explosives, now at only 36 airports.
In response, Homeland Security says it has spent $800 million this year alone to develop bomb detectors, and that 38,000 screeners have been trained to spot potential explosives, including liquids.
A former government air safety director criticizes Congress for refusing to tack a $5 user fee onto plane tickets to pay for more research.
"It makes sense that we have a user fee associated with our aviation tickets so we can upgrade our technology and better protect ourselves," says David Stone, former TSA administrator.
But some security experts say the answer should be based more on behavior, not just technology. Instead of looking for bombs, which can take countless forms, they advocate doing more to spot the people who carry them.
The model is the Israeli approach, based on observing individual passengers.
One security expert says a recent experience shows that U.S. airport employees who make the very first check — of tickets and IDs — don't even do that job well.
"I handed her my Montana driver's license, and I'm a lifelong Montana resident," says Neil Livingstone, a terrorism expert. "And she looked at it, and looked at me, and said, 'Is Montana part of the United States?'"
TSA is now testing behavioral profiling at about a dozen airports, including Miami and Washington's Dulles, and hopes it can replace those ticket checkers with trained TSA screeners. But that's months away, at the earliest.