Good stuff, though here's a Shiite counter-example:

http://www.newyorker.com/reporting/2...a_fact_filkins

Ryan Crocker, the American Ambassador to Iraq from 2007 to 2009, got a similar feeling. During the Iraq War, Crocker sometimes dealt with Suleimani indirectly, through Iraqi leaders who shuttled in and out of Tehran. Once, he asked one of the Iraqis if Suleimani was especially religious. The answer was “Not really,” Crocker told me. “He attends mosque periodically. Religion doesn’t drive him. Nationalism drives him, and the love of the fight.”
Brings to mind Kilcullen's "accidental guerrillas" and the Wild Geese of the current fight in Syria.