Details of al Qaeda’s “next generation” bomb, aborted effort to take out its designer, emerge

to recruit sources, and damages our relationships with our  foreign partners.”

“Leaks such as this have a — I don’t want overuse the word ‘devastating’ — but have a huge impact on our ability to do our business, not just on a particular source and the threat to the particular source, but your ability to recruit sources is severely hampered.”

On the same day Mueller was testifying before congressional committee, Matthew Olsen, director of the National Counterterrorism Center, addressed the issue of media leaks relating to the plot and called it “devastating.”

“Leaks do endanger people’s lives … that is not an exaggeration,” Olsen said, speaking before the American Bar Association’s standing Committee on Law and National Security, in Washington, D.C.

The Times notes that U.S. intelligence believe Asiri designed the underwear bomb worn by Umar Farouk Abdulmutallab, who tried to blow up a Delta Airlines passenger plane over Detroit in December 2009.

Asiri also designed the explosive device his brother inserted in a body cavity in an attempt to assassinate the Saudi deputy minister of interior, Muhammad bin Nayef, in August 2009. The blast killed the bomber, but  only slightly injured his target.

The CIA informant persuaded Asiri that he – the informant – should be the one to carry out the mission of placing the undetectable bomb on an American airplane in 2011.

Pistole said the plot involved “a next generation device” that was “new and improved in many respects” from earlier bombs. He said it featured “a new type of explosive that we had never seen.”

He said the bomb used “a double initiation system,” two different syringes to mix liquid explosives. It also was covered in caulk to shield its scent from machines and dogs.

“All of our explosive detection equipment wasn’t calibrated to detect that,” Pistole said. “And all of our 800 bomb-sniffing dogs had not been trained for that specific type.”

Instead of placing the bomb on a U.S.-bound plane, the informant gave the device to his CIA handlers in Saudi Arabia. He then went back to Asiri in Yemen, complaining that the device would not function as planned, and asked the bomb-maker to prepare another bomb.

The CIA then decided to take Asiri and his helpers out, but it was at that point that someone leaked the story to AP. Since the news service refused to postpone publishing to story beyond ten days, the CIA had no choice but abort the mission and extricate the informant.