"Individual Islamists may appear law-abiding and reasonable, but they are part of a totalitarian movement, and as such, all must be considered potential killers." I wrote those words days after September 11, 2001, and have been criticized for them ever since. But an incident on March 3 at the University of North Carolina in Chapel Hill suggests I did not go far enough. That was when a just-graduated student named Mohammed Reza Taheriazar, 22, and an Iranian immigrant, drove a sport utility vehicle into a crowded pedestrian zone. He struck nine people but, fortunately, none were severely injured. -snip- This...