An expert on terrorism and an expert on counterterrorism answer the two questions everyone is asking about the rise of terrorism today: why is this happening, and when will it end? Since the death of bin Laden in 2011, ISIS has risen, al-Qaeda has expanded its reach, and right-wing extremists have surged in the United States for the same simple reason: terrorism works. It's not caused by psychosis or irrationality, as the media often suggests...