> I don't think two major terror attacks with hundreds of casualties in 4 months is 'as usual' either.

Since this assumes that there is a direct correlation between migrants and the increase of terrorist acts I feel I need to inform you that ISIS is pretty well financed and not built up of poor refugees trying to find a place to live in a new, foreign world.
Thus terrorist bombings and mass migration of people fleeing oppressive regimes are highly likely two separate phenomenons.