I came across an interesting post this morning on the Journal’s Numbers Guy blog. I think we all have a tendency to think of al Qaeda as a large force, certainly they’ve been difficult to track down, but how big is the organization?

From the print edition:

A dozen terrorism scholars gave a wide range of answers when asked to estimate how many members there are, how the numbers have changed during al Qaeda’s lifespan and how many countries the group operates in. Analysts put the core membership at anywhere from 200 to 1,000. The next shell, of affiliated fighters or funders, is made up of thousands or tens of thousands. And there could be tens of thousands or hundreds of thousands of adherents, based on polls and online-forum traffic, experts say.

From the blog:

“It is likely that the Arab Spring has resulted in at least a short-term drop in new recruits from the Middle East, with the exception of the Palestinians, for whom the Arab Spring has no relevance,” said A. Aaron Weisburd, who tracks online activity by terrorist groups.

Added Joshua Sinai, a terrorism researcher at Virginia Tech’s Center for Technology, Security, and Policy, “I think the number of recruits is less than in the aftermath of 9/11/01 or Abu Ghraib but nonetheless sufficient to sustain the movement.”

Curious. I wonder what the economic weakness of the U.S. will mean for recruitment. What would promote more recruitment?