“I think we are going to see more individual terrorists and very small conspiracies,” says Brian Jenkins, senior adviser to the president of the RAND Corporation. “The good news is that we’re not going to see the Mumbais or the 9/11s [here]. The bad news is that they’re extremely hard to pick up.”…

“That doesn’t mean they’re not trying for another 9/11, as you saw in 2006” with the attempted plot to blow up at least 10 airplanes simultaneously using liquid explosives, says Gary Ackerman, assistant director for research and communication at START, a government group specializing in the study of terrorism. “The thinking is, ‘We still need to be relevant and strong, and do what we can in the meantime.’ So they’ve resorted to smaller attacks.” Among the larger, long-term goals a group like the TTP surely has, says Ackerman, is securing a nuclear weapon in a nuclear state.

Increasingly, al Qaeda and its factions also have relied on the lone actor, be it a sleeper, a recruit, or a US citizen who has become recently radicalized, as Shahzad was. “A lot of them are off the radar screen,” says Ackerman, who has been working on the first long-term study of home-grown terrorists in an attempt to find the common trigger among them.