I think that his “wife” radicalized him. To go full conspiracy theory, she was a “femme fatale” Wahhabist, a member of a terrorist cell who’s objective was to find a Western man they could convince to bring them over to various western countries. Once here, they turn their new husbands into active terrorists. Without her involvement, he would have never done this.

This is a play straight out of the Cold War KGB times. I suspect there are many more agents just like her in various countries right now.