He’s the brains behind the attempted assassination of a top Saudi counterterrorism official in the summer of 2009, the failed attack on a Detroit-bound plane Christmas 2009 and the plot that nearly brought down two cargo planes in October of 2010. In late July, the head of the transportation administration revealed new details of al-Asiri’s latest, most dangerous device, an updated underwear bomb that had fail-safe triggers and used a new kind of explosive that was even harder to detect. Al-Asiri built that bomb for an attack in May 2012 timed to the anniversary of Osama Bin Laden’s death, but the plot was foiled by a double agent who gave the device to the FBI.
Government officials say al-Asiri’s bomb plots are behind many of the security measures that have inconvenienced travelers travelling within, and to the U.S. The TSA’s use of body scanners that show a person effectively naked was designed to thwart Asiri’s underwear bombs. His printer cartridge bombs increased pressure on the cash-strapped U.S. air-forwarding industry to screen all cargo on inbound international passenger planes. The Obama Administration has alarmed some on the right and the left by killing three American citizens and dozens of Yemeni civilians with drone strikes while hunting al-Asiri and other AQAP leaders. And in an effort to find the source who leaked details of the May 2012 plot to the Associated Press, the Department of Justice pushed the limits of its investigative powers to secretly obtain call records for thousands of calls made by the AP.
Now that al-Qaeda’s original leaders are dead, captured or in hiding, the movement has dissolved into dozens of local cells scattered across the world. U.S. counterterrorism officials are debating how to go after smaller al-Qaeda affiliates. Targeting local groups could stop an ambitious cell before it gets big enough to be a threat to the U.S., but it could also mobilize terrorists who might otherwise focus on local enemies, not Americans. There is no such debate in the Administration over whether to go after al-Asiri. “He’s the main guy,” says a senior counterterrorism official. “He’s the top of any list.”