JERUSALEM — Vowing to change a region that has resisted the best efforts of presidents and prime ministers past, Barack Obama dove head first into the Middle East peace process on his second day in office. He was supposed to be different. His personal identity, his momentum, his charisma and his promise of a fresh start would fundamentally alter America’s relations with the Muslim world and settle one of its bitterest grievances. Two years later, he has managed to forge surprising unanimity on at least one topic: Barack Obama. A visit here finds both Israelis and Palestinians blame him for...