I think that things are about to get very heated.
The recent mass migration of Syrians and other middle easterners into Europe was already going poorly. The fact that a disproportionately large number of the refugees are adult men (70% or so are adult males), rather than women or children, suggests that this is not the "typical" kind of refugee crisis, where the whole family runs away from war and other hardships. These men are fleeing from conscription and/or looking for some basic work to support families back home. This means that these people likely have little reason to settle in or learn the local customs and language. After all, they're only sticking around until the war ends.
But how do you have a peaceful society where thousands of people don't know or care about the local laws, beliefs, values, language, etc? You could give a warm welcome, aka the "bleeding heart leftist" approach, but you would probably just get taken advantage of, pouring millions of Euros into supporting people who have none of your interests in mind. You could make an effort to keep them out, aka the racist right-wing fascist approach, but other than posting troops at your borders and building high walls, that's going to be difficult. Especially since EU members, aka most of Europe besides Russia and the UK, are supposed to have open borders.
I predict that over the next couple of years, right wing political parties and movements are going to gain ground in Europe. Looking at 2016, there will be major elections in the Czech Republic, Romania, and Slovakia. The leading parties in these countries at the moment are center-left, and I suspect they might lose ground to more right-wing parties. If things remain bad into 2017, expect the left and center-left to lose ground in France and Germany, the two core EU members. Despite this, Angela Merkel will likely take a hard blow due to her advocating the acceptance of migrants. And the European Union, though not likely to collapse soon, will become weaker as people view the open borders as a threat.
In the meantime, there will be violence. No huge civil wars or anything, but migrants will attack locals, locals will attack migrants, locals will attack other locals who resemble the migrants, and everyone will attack the Jews. Because Jews tend to get caught up in this sort of thing. People will still flee to Europe, if only because a terrorized country is far better than one in a civil war.
Worse, attacks are going to generally be more deadly. The most popular of terror attacks in recent years has been explosives, which isn't actually that effective. Sure, explosives are easy to make, but they're hard to make well. The thing about suicide bombers is that they only have one shot. A study of attacks in 2014 showed that the average suicide bomber killed about 5 or 6 people on average, along with themselves. But in Paris, the ratio was close to 20 killed per shooter. Even if you discount the Bataclan theater, where the most deaths occurred, the ratio was still 10 to 1. I expect that potential terrorists in Europe are taking notes and figuring out where they can get rifles, ammo, and grenades.
As for ISIL? Mission accomplished for them. They require a state of chaos and conflict to stay in power, and what I mentioned fits the bill. Even if France or whoever sends soldiers to Syria or Iraq, what will they do? Ally with the oppressive regime that everybody cheered was being overthrown? Support the Kurdish rebels, who are considered terrorists by Turkey? The Opposition Coalition, which includes about ten distinct factions and is scattered across the western part of the country?
Love and tolerate.
