"German newspaper Die Welt said authorities are investigating evidence that a 16-year-old German citizen named “Linda W.” could be among the women arrested in Mosul last week. The schoolgirl fled Germany in 2016."

Pending further information on the Canadians reportedly detained in Mosul, please consider the above. 

For a number of reasons, young people may reject the status quo and take up what they see as an idealistic cause. In the general sense, god bless them for doing so. Nevertheless, they are as prone to fallibility as is, say, the Government of the United States when it violated all international norms and invaded Iraq in 2003. (Did I mention that invasion spawned Islamic State? Perhaps another time.)

The rational counter to any extremist ideology is moderation and forbearance. This is true generally, and especially when it comes to dealing with young offenders.