Senior U.S. officials continued to withhold certain details, including the location and status of the individual — described by officials as a Saudi informant — who penetrated the terrorist group posing as a bomber and then turned over the device to authorities after leaving Yemen.
But comments by White House counterterrorism adviser John O. Brennan and others made it clear that the involvement of the CIA and its partners went well beyond simply watching the plot unfold.
“We’re confident that neither the device nor the intended user of this device posed a threat to us,” Brennan said in an interview on ABC’s “Good Morning America.” “We had the device in our control, and we were confident that it was not going to pose a threat to the American public.”
The bomb arrived at an FBI laboratory in Quantico about a week ago and is being examined by explosives technicians, law enforcement officials said. One said the explosive was made from a chemical compound that was “built to get around U.S. security and had the potential to do that.”
The emerging details help to illuminate the evolving tactics being employed by both sides in what U.S. officials have come to regard as the most critical counterterrorism front.
The plot shows that al-Qaeda’s franchise in Yemen remains committed to mounting attacks against Western targets even after its most prominent advocate of such strikes, the American-born Anwar al-Awlaki, was killed in a drone strike last year.
The disruption of the threat also indicates that the CIA and other agencies have gained significant traction on their target two years after President Obama began deploying more spies, eavesdropping equipment and armed drones to the Arabian Peninsula.
CIA officials declined to comment on the mission. Other officials spoke on the condition of anonymity because of the sensitivity of intelligence operations.
A senior U.S. intelligence official said spy agencies were able to keep tabs on the location of the bomb, as well as those involved in plotting how it would be used, before it was intercepted in another country in the Middle East, thought to be Saudi Arabia.
“We know the route this thing took in terms of its movement,” the official said.
The device was described as an updated version of a design that al-Qaeda in the Arabian Peninsula, or AQAP, has used in a series of plots, including an attempt to blow up a Detroit-bound airliner on Christmas Day 2009.