Irrepressible individualist and iconoclast Pat Tillman walked away from his $3.6 million NFL contract in May 2002 to enlist in the United States Army. Deeply troubled by 9/11, he felt a strong moral obligation to join the fight against al-Qaeda and the Taliban. Two years later, he died on a desolate hillside in Afghanistan. Though obvious to most on the scene that a ranger in Tillman's own platoon had fired the fatal shots, the Army aggressively maneuvered...