The Crusader’s learned enough about them. What was left to learn after the 1993 World Trade Center bombing and then 9/11 and every beheading since then?
Only one lesson. The lesson that political correctness is a waste of time. That is the only lesson left, and it will come when the Jihadis do something that even the most lily livered Leftie cannot ignore. Sooner or later they will pull a Boko Haram in an area that cannot be ignored, and the last vestiges of political correctness will fade into the night. That will be the trigger.