"Almost 2.5 million Americans have served in Afghanistan or Iraq since September 11, 2001. C.J. Chivers has reported from both fronts from the beginning, walking side by side with combatants for more than a dozen years. He describes the experience of war today as it is endured by those most at risk--the camaraderie and profound sense of purpose, alongside courage, frustration, and moral confusion mixed with technical precision. In these remote places...