January 07, 2010 CNN

ROBERTS: Well, the threat from so called homegrown terrorism may be real, but a new study says it's not as great as most people think. Duke University credits the American-Muslim Community with limiting radicalization by policing itself.

Joining us now from Durham, North Carolina is Ebrahim Moosa. He is a co-author of the Duke study. And professor of Islamic studies there, and from Fargo, North Dakota, Jarret Brachman. He is the author of Global Jihadism and an assistant professor at North Dakota State.

Thanks very much, gentleman. Both are being with us.

Let's go to you, first of all, Ebrahim.

When you look at this study, and I've got it here. It's a lengthy study. How big a problem did up find radicalization is in the United States. And is there some way to quantify it?

EBRAHIM MOOSA, PROFESSOR OF ISLAMIC STUDIES, DUKE UNIVERSITY: John, it's very difficult to quantify it. But, you know, in the first areas that we looked at Detroit -- sorry, Seattle, Buffalo, Raleigh, Durham area and also Houston. In those areas we found that the communities are taking active steps in order to combat whatever elements of radicalization there is in their communities, et cetera. And this is a very, very healthy sign.

ROBERTS: You found that 139 people had been arrested and accused of -- arrested or accused of planning or carrying out terror-related violence since the September 11th attacks. Your co-author, Charles Kurtsman, said that the study was a demonstration that the fear of radicalization, homegrown terrorism is out of proportion to the actual threat.

Jarret, do you agree with that?

JARRET BRACHMAN, AUTHOR, "GLOBAL JIHADISM": Well, I mean, that's the inherent nature of terrorism is that it doesn't -- you don't need a lot of people to create a lot of fear. And so, you know, in this case, I think their radicalization is a problem. I think we need to address it in context as the study says, but it's something that law enforcement is going to continue to wrestle with for a while in this country.