Airport screening dare not stand pat

Terrorists have innovated, and that means airport security must respond.

The debut of the underwear bomb, even though it fizzled Christmas Day without seriously damaging a Detroit-bound jet, has strengthened the case for widespread use of scanners that see through clothes.

The traveling public is weary of intrusive screening, but the Transportation Security Administration has answered major objections to the electronic strip search.

Privacy is respected, as much as possible. Passengers' faces are blurred, and agents checking the images for contraband do not see the actual person they're screening. Digital images cannot be saved or posted on the Internet, the TSA promises.

Passengers may opt for a physical pat down if they object to being bathed in electromagnetic waves whose reflected energy creates an anatomically accurate 3-D image.

The devices are costly and are not foolproof, but such is the nature of all anti-terror barriers.

Some argue that the best plan is to identify and stop terrorists before they get to the airport. But the clear need for better intelligence, which President Obama stressed Tuesday, is no guarantee we'll get it.

A new report on anti-terrorism in Afghanistan, where there is an extensive U.S. presence on the ground, points out how difficult it is to identify friend from foe.

Little of what is said on the radio there is translated. U.S. forces don't know what's happening in town meetings, much less in the terrorists' camps. The suicide bomber from Jordan who killed seven Central Intelligence Agency employees and contractors recently at their base in Afghanistan was thought to be working for us.

Because the intentions of everyone wanting to board a plane cannot be known, tight screening is essential.

The success of metal detectors and strict limits on liquids have reduced terrorists to carrying small bombs hidden is places that until now have gone unchecked. From that perspective, we're winning.

But as threats evolve, so must our defenses. The Washington Post reported last year that in Sri Lanka it has become necessary to check inside women's bras for bombs. That's because in the civil war there, more than two-thirds of the Tamil Tiger suicide bombers have been women. The newspaper said the country is "testing the boundaries of what people are willing to endure for the sake of their safety."

So are we.

Two years ago, we said that before airport security requires all of us to reveal our intimate selves in a virtual strip search, we need to know what is being gained by the wholesale loss of privacy. The underwear bomber has made the threat clear.

The next question is how far the intrusive searches will go.

Must we be scanned when entering a football stadium, courthouse or shopping mall? No. It is hard to imagine living in a nation so insecure.

But the vulnerability of airplanes makes the loss of privacy at the airport an indignity we reluctantly accept.