“Why don’t Muslims crack down on their terrorist elements” has been a pretty standard question since 9/11.
The short answer – they, largely, are:
It used to be that there were plenty of mosques in the West run by radicalized, or very conservative, clerics. But no more. Since September 11, 2001, Western nations have cracked down. Radical clerics were either expelled from the country (these guys tend to be migrants), or police investigations of criminal activity by these firebrand clerics put them in jail, or on the run.
Which is not to say there was never a problem:
Turns out that in the 1980s and 90s, a lot of mosques had been taken over by a small number of radical members. Threats and violence were used, and it often got quite ugly. This was ignored until the 1990s, and not tolerated much at all after 2001. While this kept the radical Moslems quiet, it did not always change their attitudes. But these men were usually migrants, often from the same country, or region, as their fellow congregants.
As with so many things, 9/11 changed all that:
After 2001, Moslems in the West, particularly the United States, knew that they were responsible for the terrorist activity of Moslems they worshiped together with. They could usually recognize another migrant who might be up to something dangerous. Action could be taken to stop it, or drive the troublemaker away (or turn him in to the cops). But the new converts were harder to read. Thus the growing tendency to scrutinize those seeking instruction to become a convert.
And it’s having an effect:
Even before September 11, 2001, al Qaeda warned its agents to not hang out with American Moslems, who were known to turn in suspected radicals. Now American Moslems are letting the FBI know about suspicious new guys seeking to convert. That has led to the arrest of some active terrorists. But in many European countries, local Moslems are less prone to let the police know of someone suspicious, and there are more active Islamic radicals (because the Middle East is closer, and Moslem migrants are less likely to be accepted by the natives.)
Unmentioned in the piece; is the Twin Cities’ extremely fundamentalist Somali Muslim community an exception?