Sayfullo Saipov, the Uzbek-born immigrant who ran down more than a dozen people with a rented truck this past week, touched a presidential twitter stormand a debate about immigration.

This debate is misguided. Though some immigration reforms are needed, this terrorist attack should make us think about two types of self-radicalization: the personal transformation of a peaceful migrant into a determined killer and Uzbekistan’s unique use of religion (what scholars call “self-Islamization”) to bind together that Central Asian nation. Saipov’s experiences in the U.S. from 2010 onward and the policies of his homeland combined to make him into the killer that he is.