“There is no place for bigotry in effective counterterrorism,” Professor James Forest, the director of the graduate program in security studies and interim director of the Center for Terrorism and Security Studies at UMass Lowell, told me. “Terrorist groups like al Qaeda and Islamic State thrive when they can exploit the vulnerable seams within a society, when they can exacerbate prejudices.”

Arie W. Kruglanski, professor of psychology at the University of Maryland, has written about how ISIS recruitment strategy is based on psychology, not theology.  And within that context, Kruglanski told me: “The refugee debate could fuel the bitterness and sense of grievance of young Muslims anywhere and could be used by ISIS propaganda machine to enhance anti-US sentiment and boost recruitment.”

“Counterterrorism tries to do two things,” explained Professor Max Abrahms, a political scientist at Northeastern University who studies terrorism. “You try to neutralize existing terrorists and you try to not breed new ones. The surest way to breed new ones is if you’re indiscriminate—for instance, punishing non-violent, moderate Muslims.”