The scheme never had a chance, though, because the would-be bomber was actually a double-agent working for Saudi Arabia's security services. Saudi officials worked with the CIA to deliver the sophisticated new bomb directly to the U.S. government, according to current and former U.S. officials briefed on the situation.
The operation was a victory on multiple fronts. Not only did it prevent an attack and give the U.S. a look at al-Qaida's latest deadly invention, but the double agent also provided some of the information that led to the drone strike last weekend that killed Fahd al-Quso, two former officials said.
Al-Quso, whom the U.S. believes was al-Qaida's chief of external operations in Yemen, personally met with the would-be bomber and instructed him to pick a U.S.-bound plane to attack on the day of his choosing, the officials said.
The current and former officials spoke on condition of anonymity because they were not authorized to publicly discuss the operation.
The FBI is still analyzing the explosive but officials described it as an upgrade over the bomb that fizzled aboard a plane over Detroit on Christmas Day 2009. The new device contained no metal and utilized the chemical lead azide, which is known as a reliable detonator. After the Christmas attack failed, al-Qaida used lead azide as the detonator in a nearly successful 2010 plot against cargo planes.
Despite the sophistication of this latest underwear bomb, security officials said they believed bombs like it could have been detected by airport body scanners or security pat-downs, which have become commonplace in U.S. airports since the failed Christmas 2009 attack.
Procedures overseas, however, can be a mixed bag. The U.S. cannot force other countries to permanently adopt the expensive and intrusive measures that have become common in American airports over the past decade.
"I would not expect any real changes for the traveling public," said House Intelligence Committee Chairman Mike Rogers, R-Mich. "There is a concern that overseas security doesn't match ours. That's an ongoing challenge."
The Transportation Security Administration sent advice Tuesday to some international air carriers and airports about security measures that might stave off an attack from a hidden explosive. It's the same advice the U.S. has issued before, but there was a thought that it might get new attention in light of the foiled plot.
All passengers on U.S.-bound flights are checked against terrorist watch lists and law enforcement databases.
"Even if our technology is good enough to spot it, the technology is still in human hands and we are inherently fallible," said Rep. Adam Schiff, D-Calif., a member of the House Intelligence Committee. "And overseas, we have varying degrees of security depending on where the flight originates."
Authorities believe that, like the Christmas bomb and the printer bombs, this latest device is the handiwork of either al-Qaida's master bomb maker in Yemen, Ibrahim Hassan al-Asiri, or one of his students.
In the meantime, Americans traveled Tuesday with little apparent concern.
"We were nervous - for a minute," said Nan Gartner, a retiree on her way to Italy from New York's John F. Kennedy Airport. "But then we thought, we aren't going anywhere near Yemen, so we're OK."
___
Associated Press writers Matt Apuzzo, Adam Goldman, Eileen Sullivan, Ted Bridis, Bob Burns, Bradley Klapper and Alan Fram in Washington, Ahmed Al-Haj in Sanaa, Yemen, Verena Dobnik in New York, Paisley Dodds in London, Matthew Lee in New Delhi and Slobodan Lekic in Brussels contributed to this report.
