The immigration issue could threaten the EU?

Just heard on CNBC.

Germany has supposedly said to immigrants that once they're in they won't be forced back out.  That is what's leading to the craziness with the trains.  Meanwhile Ms. Merkel is saying that each nation must take hundreds of thousands of immigrants and they're getting pushback.

The analyst on CNBC is saying that this could be the biggest threat to the EU since its birth.  He went on to say that difficulties with integration into European society would see generations of tension.

Sounds like the EU is in for a rough ride.  Popcorn please!