"Since 9/11, there have been over 2,300 arrests connected to Islamist terrorism in Europe in contrast to about 60 in the United States." Thus writes Marc Sageman in his influential new book, Leaderless Jihad: Terror Networks in the Twenty-First Century (University of Pennsylvania Press).

This one statistical comparison inspires Sageman, in a chapter he calls The Atlantic Divide, to draw sweeping conclusions about the superior circumstances of American Muslims. "The rate of arrests on terrorism charges per capita among Muslims is six times higher in Europe than in the United States." The reason for this discrepancy, he argues, "lies in the differences in the extent to which these respective Muslim communities are radicalized." He praises "American cultural exceptionalism", admonishes European governments "to avoid committing mistakes that risk the loss of good will in the Muslim community," and urges Europeans to learn from Americans.

Sageman's argument rehashes what Spencer Ackerman wrote in a New Republic cover story of late 2005, when he found that "Europe's growing Muslim culture of alienation, marginalization, and jihad isn't taking root" in the United States.

But Sageman's entire case is premised on the figures of 2,300 and 60 arrests. Aside from possible other causal explanations for these differences, such as the European legal system permitting more latitude to make terrorism-related arrests, are those figures even correct? He supports them with only a brief, vague footnote: "Updating Eggen and Tate, 2005; Lustick 2006: 151-52 agrees with this estimate." Here, "Eggen and Tate, 2005" refers to a two-part newspaper article and "Lustick 2006" sources a discredited extremist screed.


From the text, it can be inferred that

Sageman's figures are considered to be very accurate and show exactly the far superior number of terrorists arrested in Europe when compared to the American ones.