When I first started grad school, I was unimpressed with the gonzo libertarians who were opposed to religion and voting. I didn't really understand the appeal of undermining your acceptance by the average citizen just to maintain your libertarian street cred. I met one kid at a conference who insisted that Iran should have nuclear weapons as a deterrent for the United States. Now, I agree that the United States needs a deterrent in the world (everyone does), but giving nuclear weapons to Iran would guarantee another Holocaust. I oppose all kinds of Holocaust denying, both past and future.
Anyway, Open Borders is another example of libertarians working hard to marginalize themselves. The shame is that those paying the real cost are the refuges that won't be allowed to flee their persecutors because some libertarian enjoying peace and comfort thinks he can't compromise without being a sell-out.
Millions of people need to get out of Syria and into Europe or North America. But demanding the doors be thrown wide open is a great way of making sure they don't get the chance. Firstly, I don't see how anyone can deny that there are terrorists in the world who wish to harm Westerners. ("But the West brought it on themselves!" You're insane. We're not debating cause, we're acknowledging effect.) Terrorists would be negligent if they passed up the chance to join the mass of refugees. So there must be controls and a vetting process.
Secondly, economies do not instantaneously equilibrate following such population shocks. You can't ignore the Westerners' concern about the adjustment costs. I know, those fleeing terror don't have that much of a concern about the growing pains the West will experience. So there needs to be a two-stage solution that will allow for immediate relief from war and a gradual joining of Western society.
I think the G8 countries should announce objective criteria for refugee acceptance and commit to accepting as many refugees as meet these standards. Then, stable regional partners such as Turkey should agree to house refugee camps. At the camps, refugees have medical and safety evaluations. Once they are vetted, they get on a plan and begin their new lives in the West. This would spread the burden (and provide a demographic boost to dying countries like Italy and Japan), while protecting Westerners from disguised terrorists.
Anyone who can't support a plan like that is too interested in his libertarian fanboy status.