'The threat is already on the inside'

Well Done Rosa Brooks - writing in Foreign Policy about that and 'nine other truths nobody wants to hear about terrorism' at http://foreignpolicy.com/2015/11/20/the-threat-is-already-inside-uncomfortable-truths-terrorism-isis/?utm_source=Sailthru&utm_medium=email&utm_campaign=New%20Campaign&utm_term=Flashpoints

I hope someone has pointed out to Donald Trump that closing borders to his chosen categories of undesirables won't solve the problem.