i also want to add this fact:
I understand being totally freaked out by the sight of 30,000 homeless people trudging through your small, european town. I get that and I would probably be freaked out too.
The refugees coming to North America aren't those people. They are people who have been living in refugee camps in Jordan, Lebanon etc already. They have been vetted by the UN, they have ID, many have already started the process of coming but are mired in stalled paperwork etc.
These people cannot just jump in a dinghy and come across the ocean to get here so our situation is different. It will be controlled and regulated. Trust me, ISIS fighters have not embedded themselves in a refugee camp for two years waiting for their chance to come to North America because there are enough radicalized assholes who already live here and others who have valid passports who can travel freely anyway.
These are families who have had to flee because they have no home left, their villages and cities have been taken over by murdering, pillaging criminals. Most of the big wigs in ISIS are former drug lords and criminals. They currently live in tent cities run by the host nation and the UN. The camp north of Amman is the largest in the world and they do their best but there is not enough money or room for a place like Jordan to take anymore Syrians (remember, they are also full of Iraqis - Iraqi and Syrian christians usually choose Jordan first since it's safe for them there as Christians live freely in Jordan).
The word that Middle Easterns use for ISIS is Daesh and it is considered very insulting - they refuse to dignify the criminal organization by using the term ISIS.
Here, i found this which explains it pretty well