US News

Undie bomb is hide & eek!

He could have breezed through security at any airport.

A terrorist wearing the latest underwear bomb would not have been caught by the TSA’s most conscientious human screeners or its highest-tech fullbody scanners, experts told The Post yesterday. But the country ducked a disaster by employing an age-old weapon: a double agent.

With the help of American allies in Saudi Arabia and Yemen, the secret agent inserted himself into the terrorists’ secret inner circle, and became so trusted, the thugs accepted his offer to board a US-bound plane wearing the bomb.

Instead, the agent turned it over to the United States.

But experts said that as far as future suicide bomb attempts are concerned, current technology is not good enough to find nonmetallic explosive devices like the newest underwear bomb — despite Homeland Security Secretary Janet Napolitano’s assurance that there was a “high likelihood’’ the bomber would have been stopped.

One top law-enforcement official insisted, “They would not have gotten him.’’

The only surefire way to detect nonmetallic explosive devices is using bomb-sniffing dogs, but that’s impractical at crowded airports.

There aren’t enough dogs to check every passenger at every security line.

And travelers would be even more offended than they are now if they were sniffed by a dog before boarding any flight.

The underwear device, disclosed Monday, was very similar to the one a terrorist wore on a Detroit-bound plane on Christmas Day 2009.

That one didn’t go off because the detonator failed.

But the new bomb included a more sophisticated trigger that used a chemical called lead azide.

The “suicide bomber” in the most recent scheme had already been told to choose a date and buy a ticket when he not only disclosed the plot, but provided information that allowed the United States to launch a drone attack that killed the operations chief of al Qaeda’s Yemen affiliate.

The suspected bombmaker in both instance, Ibrahim Hassan al-Asiri, is still at large.

“And we’re concerned about that — no question about it,’’ Police Commissioner Ray Kelly acknowledged at a press conference yesterday.

While the most sophisticated airport-scanner machines can’t detect explosives, they do check for differences in density between fabrics.

But the effectiveness of that function depends on the ability of the human screeners examining the images.

“Frankly, the caliber of the screeners is not that good. It’s kind of hit or miss,” one source said. “The equipment is wonderful — but it isn’t bulletproof.”

The new underwear bomb is being studied by the FBI at its lab in Quantico, Va.

“The FBI is testing to see if it would be detected or could go through security,” said an airport official.

Another source said FBI technicians want to figure out “how you could detect the materials utilized in constructing this bomb before it gets on a plane.”

Napolitano, speaking yesterday in Washington, said, “There is a high likelihood that [the bomb] would have been detected had he boarded a flight in the United States.’’

She did not address the issue of overseas flights to the United States.

White House spokesman Jay Carney told reporters, “We are constantly adjusting our . . . measures that we take to counter threats like this in the aviation industry.”

Meanwhile, another Homeland Security official said that the full-body machines have caused such a firestorm that “a lot of the airports are loathe to use . . . them.’’