MELISSA BLOCK, host: This week, we're marking the 10th anniversary of the 9/11 attacks. And today, we ask: Just how close is the U.S. to defeating al-Qaida? Osama bin Laden knew the U.S. would retaliate after 9/11. So even before the attacks, he began dispersing the group's members - sending fighters home from training camps in Afghanistan. He also nurtured supporters in Iraq, Pakistan, Yemen and Somalia, an effort to turn al-Qaida into a fundamentally different organization. NPR's Dina Temple-Raston explains why, even with bin Laden dead, it might be too early to declare victory.
DINA TEMPLE-RASTON: If you ask terrorism experts for the one person in the U.S. who's been tracking al-Qaida longer than anyone else, they invariably mention someone you've probably never heard of - a small bespectacled woman named Barbara Sude.
BARBARA SUDE: I'm Barbara Sude. I'm a former analyst from the Central Intelligence Agency, and I currently work at the Rand Corporation.
TEMPLE-RASTON: Barbara Sude was tracking al-Qaida for the spy agency for two decades, long before the group became the brightest dot on the U.S. radar screen. So she's uniquely positioned to say how today's al-Qaida is different from the one that attacked the U.S. 10 years ago. And she doesn't see a defeated organization.
SUDE: It's become much more adaptable. It's learned to live with moving around to different locations. They are taking people from other nationalities. They've got a lot of Europeans and have U.S. people also working for them, more than in the past. So I think there's something going for them in that direction.
TEMPLE-RASTON: Intelligence officials estimate there are about 4,000 al-Qaida followers around the world. And they say today's al-Qaida is younger and better educated and, as important, more geographically diverse than the group bin Laden created.
SUDE: Bin Laden always wanted to have different regional organizations joining the team and it didn't necessarily work out for him when he was in Sudan or the early days in Afghanistan. But his organization seems to have achieved that to a degree in getting, like, al-Qaida in Iraq, al-Qaida in the Arabian Peninsula and al-Qaida in the Islamic Magreb to join - clearly join with them.
TEMPLE-RASTON: She mentioned three groups there. Al-Qaida in Iraq is in the process of making a comeback. Al-Qaida in the Arabian Peninsula, based in Yemen, is now the most potentially dangerous branch of the group taking aim at the U.S. It's already launched two attacks - the 2009 Christmas Day attempted airline bombing and the failed cargo bomb plot last Thanksgiving. And the third group, al-Qaida in the Islamic Magreb, based in North Africa, is helping funnel al-Qaida recruits to Somalia. All this in spite of the death of Osama bin Laden in May.
BRUCE HOFFMAN: It's a bit rash, even despite the death of its founder and leader, or the killing of its founder and leader, to count them out yet.
TEMPLE-RASTON: That's Bruce Hoffman, a terrorism expert and professor at Georgetown University. He says al-Qaida is suffering because of U.S. drone attacks, assassinations and recent arrests. Still, he says, the group is adapting.
HOFFMAN: Even while al-Qaida central or the core al-Qaida group is substantially weakened compared to what it was even two or three years ago, the problem is that the periphery or the al-Qaida affiliates and associates are arguably even stronger today than they've ever been.
TEMPLE-RASTON: Depending on how you keep count, al-Qaida has seven or eight locations from where they can plan, train and launch operations against the U.S. - places like Yemen and Somalia. In the run-up to 9/11, bin Laden had just one - Afghanistan. And the number of groups embracing al-Qaida's ideology also seems to keep growing. Just in the past month, al-Qaida has shown up in Nigeria. Military intelligence officials are watching for signs of al-Qaida in Libya. Al-Qaida's ability to pop up where officials least expect it hasn't changed much. And that's what keeps former CIA analyst Barbara Sude on alert.
SUDE: You never know where they have people, how many they have, if they have a plot that's already in train. They could be completely weak, and they never got anything off the ground. And bin Laden is dead and that's, you know, they are fading away. And they could fade away. At least, central could fade away. But did they have something already started? Are people moving into place?
TEMPLE-RASTON: Exactly the sort of question her former colleagues at the CIA are looking into as we approach the 10th anniversary of 9/11. Dina Temple-Raston, NPR News, New York.