Al Qaeda still keeps the top US counterterrorism chief awake at night, despite the hammering the group has taken during Mike Leiter's nearly five years on the job.
But as he leaves office, it's not Al Qaeda central he worries most about.
It's the spinoffs focused on recruiting Westerners to join the terror cause, and on staging small-scale attacks that require less training and expertise than the ones launched on Sept. 11, 2001, Leiter says. He warns that the core group may even end up emulating them.
Leiter, the head of the National Counterterrorism Center, told The Associated Press in his last scheduled interview that Al Qaeda is weaker, thanks to years of pursuit by a network of US intelligence, law enforcement and special operations, followed by the Navy SEAL raid in Pakistan in May that killed its leader, Osama bin Laden.
"They have to ask themselves, 'How did this happen?' and 'If it happened to bin Laden, then it can obviously also happen to me,'" Leiter said.
Continued pressure on the terror network is needed, he said.
Leiter played a key role in the evolution of this undercover campaign by helping to get the NCTC off the ground. An experiment in intelligence-sharing mandated by Congress after Sept. 11, it was meant to blend the strands of terrorist-related information from the CIA to the FBI and local law enforcement to the State Department. The aim was to target Al Qaeda and prevent another attack.
While Leiter is less well known outside Washington, the Harvard-trained lawyer is one of the ultimate counterterrorist insiders, serving two administrations in 4 ½ years, first as deputy and then as director of the NCTC. Before that, he served in government for more than 20 years, including time as a Navy pilot flying EA-6B Prowlers in missions over Iraq and the former Yugoslavia.
Leiter watched the bin Laden raid unfold in the White House Situation Room with the president's national security team. He describes it as one of the most heart-stopping moments since his days of landing on an aircraft carrier in bad weather. And one of the most satisfying.
With bin Laden gone, he says the shreds of Al Qaeda central's leadership may pursue smaller, harder-to-stop attacks.
"In my early days of the Bush administration, we still had a greater fear of a catastrophic attack," including the use of chemical, nuclear or biological weapons, Leiter said. After the operations in Pakistan, "I'm far more concerned now ... with the small-scale shooter."
While smaller attacks mean fewer casualties, they'll be harder to spot and stop, Leiter said. He points to plots like the explosive material secreted into printer cartridges in US-bound cargo planes last fall.
And there's the attempted Christmas Day bombing of a Detroit-bound airliner in 2009. Nigerian-born Umar Farouk Abdulmutallab is accused of trying to bring down the plane with explosives in his underwear.
That plot led critics from the White House to Capitol Hill to question whether the entire national security apparatus had learned anything since Sept. 11 — and whether Leiter in particular was doing his job.
Leiter said they had indeed learned from the 2001 attacks and that the material was being shared. But, he added, that was no guarantee they'd see the next attack coming in time to stop it.
Intelligence sharing is a matter of course, he insisted in the AP interview. Members of every major agency confer with the White House by secure videoconference three times a day to share information, and specialized units within the counterterrorism center work problem areas together, combining analysts from the CIA, FBI, the eavesdropping National Security Agency and others to focus on specific geographic regions.
Leiter said the problem is they now have so much information, it is difficult to pick up the patterns that point to one threat or suspect as more dangerous than another.
That leaves his agency and others unable to guarantee 100 per cent success, any more than police can head off every school shooting or workplace shooting, Leiter said. He called on Americans to be more resilient, to bounce back faster from attacks with fewer recriminations against the government for allowing attacks to happen — a personal mantra during his NCTC term.
"Otherwise, we've given Al Qaeda a win," he said.
Leiter described the evolution in the counterterrorist campaign from the Bush administration to President Barack Obama's as more of an acceleration of techniques already being tried than a wholesale change. An example: the use of special operations raids in preference to the costly, full-scale invasions of Afghanistan and then Iraq, two countries the Obama administration has made clear it would like to leave.