BOWE Bergdahl arrived in Afghanistan ready to kill. Like many soldiers heading into a war zone for the first time, the 22-year-old US army private was eager. As he and his unit prepared for battle in late 2008, he approached his squad leader at their Alaska military base with a memorable question. “The first thing he said was: ‘Can I cut off the face of the first Taliban I kill and wear it like a mask?’” said Josh Korder, an army soldier who said he couldn’t believe what he was hearing. The bravado didn’t last. The Private Bergdahl’s view of...