Problem with Migration is not so much the Culture.
But the Attempt to do this on Absolute Minimal Budged.
If you want to take large amount of People from a Different Culture in. You need to Educate them. You need to Teach them just where they are and what the Laws are.
But most of all you have to give them something to do and allow them to Earn their Living.
Currently these People are often Stowed Away somewhere. With an absolutely lack of everything and are not allowed to even work to improve their Lives.
They often dont even know that the Laws are Different and dont Understand if others Tell them cause they dont Speak the language.
So being Stored Away they tend to do what they can do without needing to talk know the laws or having a permit to work.
They get Criminal.
Europeans would be the same if you Shoved them with 30 People into an 2 Room Apartment of lets be generous and say 50m² Living Room while telling them. Well sit there and Rot you aint allowed to do anything.
The Government needs to use some Money to actually Integrate these People.
Teach them the Basic Laws and the Language. And heck most of all Allow them to Work.
No Need for them to Freely Flood the Market. Simply have them Work under State Supervision for example in smaller Jobs that in the past was done by the Guys who Denied Military Service and thus did Civil Service instead. These Jobs generally dont need any bigger Education Level and can be really useful.
They also dont cost the remaining Populace any Jobs because they are usually stuff not being done unless you have the People. (Or which are usually Filled in the Books for next 3 Decades because the few Paid State Workers are running all over the Country and have not finished half their Round before the Stuff they did at the Start is already Decayed and needs Work again.....)
And after they have been Granted Permits etc they can then Join the Community not only with a bit of Starting Money and an halfwat acceptable understanding of Laws, Culture and Language. But even with some Working Experience and thus knowing what they are Worth and thus not resulting in Dumping Salaries for the Native Population.
Its similar to the Crisis Regions.
Who in their Sane Mind can seriously Believe that you can keep an Country with 10 Million Population under Control with maybe 5000 Soldiers we got there.
Its logical that ISIS etc will Recruit there. After all the 5000 Soldiers cannot Possibly Control this Area for Heavens sake.
And the same Applies here as well.
You cant Seriously Expect that you are going to Integrate 2 Million Refugees with a Budged with which you usually Integrate maybe 50.000 Immigrants of which most had Prior Knowledge and Courses to Increase their Acceptance Chances.
The Question is tough.
How is that Related to the Brexit ?
EU is pretty much Purely Western Culture and most People Speak English and have at least Basic Education.
You dont get Muslim Immigrants from the EU.
Much less Refugees.
So Leaving the EU is not helping this Issue at all.