Aziz Abu Sarah knows what it’s like to have been so entrenched in his views that to give an inch, even to acknowledge someone else’s suffering, feels like a betrayal. And now the Palestinian peace activist, who works to get American Muslims and Jews listening to each other’s perspectives, is seeing the problem all around. “I have friends who are American Jews and friends who are Arab American and they both only feel the pain of one side and completely ignore the other. Even some people who are not directly connected to either side have decided to be hardcore for...