Does bad math lead to fear or does fear lead to bad math? Hmmm. I saw online last night folks arguing about the 25,000 refugees that Canada has promised to take in, that one might be bringing in terrorists along with them. The line was: if one percent of these folks are terrorists, then you are importing 250 terrorists. Wow! Scary! Bad math!

There, of course, are expected utility/utilitarian calculations one could make. Let's say that of the 25000 refugees that Canada would take in, 1% will die if we don't: 250. Let's say that of the 25000 refugees, .01% or 2.5 (still a historically high number) would become terrorists that end up killing 100 Canadians. Are the lives of 100 Canadians worth more than 250 refugees? Of course, I am just playing with numbers and I am not a philosopher who is an expert in the trolley problem.
What this does seem to be is an outsized fear that might cause us to do what is against our values, against our character. We already see American politicians dancing to the tune of fear: Trump threatening the first amendment by offering to close mosques, governors saying that they will not take in refugees, etc. The aim of the terrorists is to cause us self-inflicted wounds--like rendition, torture, Abu Grhaib (the whole Iraq invasion), Guantanamo, etc. The way to defeat the terrorists is not to ignore their attacks but not to over-react to them and not to change who we are and what we do as a result of their attacks.
Canada and the U.S. are countries that have self-images (mostly but not entirely accurate) as countries built on offering refuge. It is a selective history, but still key to the identities of both countries. It makes no sense to sell that out now because of some fear. Both countries have had less damaging homegrown attacks precisely because they are far better at absorbing those who are different. This is a core strength of what it is to be American and what it is to be Canadian. To reject the refugees based on the fear of the .1% or the .01% or the .001% is to be un-American, to be un-Canadian. And to be really bad at math.
Both countries are resilient enough to handle the refugees and all that they bring with them. It sounds trite that we would be letting the terrorists win if we don't accept the refugees and if we given in to our fears, but it will still be true.
Islamophobia is for the weak, xenophobia is handy for politicians if we support their efforts to divide. We are better than that. We make mistakes, but we are better than that. Perhaps my math is tainted by a bit of wishful thinking in the form of hope, but my understanding of ethnic conflict tells me that Yoda was right.