Lol, bub you're preaching to the wrong guy on that, I don't even consider NY times, Huff, WA, news, so that ain't it.
Hard evidence, well seems every one of those isis videos starts off with the same thing, the aftermath of one of our attacks, guessing they keep with the same theme for a reason.
It's the same crap with any armed faction, be it isis, or say our USMC.
Recruitment is recruitment when it comes to amasing a armed group to follow orders.
Also, MANY American soldiers are there first and foremost for a paycheck too, go to a MEPS center, you'll get tons of, "wanted to get out of my home town, no good jobs" "shooting stuff" "they'll pay for college" "driving a tank" etc, and the same minority of "true believers".
As far as ideals and false damage, we do the same crap, be it WMDs in Iraq, scare tactics, or ignoring warnings, war is war is its always for the same reason, money and power.
Same chit diffrent toilet.
Personally I wish all these power hungry war mongers would just go at it man to man, instead of bringing tons of other people into their "causes" who otherwise wouldn't give two craps about the "enemy"