Could ISIS Plant Its Black Flags In Europe?

You betcha. ISIS members have the will, the resources and all the time in the world to get the job done.

And what do we have to defend ourselves from the onslaught? Well, according to the above link, we shouldn't even consider putting our filthy infidel boots on the ground because,

As we saw in Iraq, putting boots on the ground in a Muslim country only incites people to join ISIS. We have to be involved in the intelligence game, use airpower and diplomacy to rally our sometimes-reluctant allies into doing more.

Intelligence; airpower; diplomacy: yeah, that should do it.

That and our "empathy" for fleeing "refugees" (only a small number of whom are likely to be hot for ISIS/jihad).

The Jewish version of this "empathy"/humanitarianism is known as "tikkun olam" (which in our time, as I've come to realize, is Hebrew for "sh*t for brains").

And since we're on the topic of Syrian refugees, it's a good thing Syria's Jews were rescued some years ago, because had they remained, by now they'd all be dead.