They made a choice and decision. It was their choice to follow the brutal path of the so-called Islamic State, their decision to declare Canada and Canadians a sworn enemy. No matter, they were Canadian.
Canada represented Western cultural decadence. The Islamic State offered the option to commit acts of barbarism: to set fire to a Jordanian fighter pilot locked into a cage; to hurl gays to their deaths from rooftops: to repeatedly rape young girls kidnapped from their families.