This situation wouldn't be nearly as bad if there wasn't a welfare state, citizens were armed, and there was a strong filtration process (which also puts a reasonable cap on how many come in at a time). But Europe has none of these, and America and Canada has only one (which is certainly at risk).
Refugees have been handled before, and while it's never been amazing, it's definitely been done far better than this. This whole crisis is one big shitshow of incompetence and the very dangerous mix of good will and stupidity. Guess we'll have to get our shit fucked up before we learn.