FORT BRAGG, N.C., Sept. 17 — From his position about 100 yards away, Master Sgt. Troy Anderson had a clear shot at the Afghan man standing outside a residential compound in a village near the Pakistan border last October. When Capt. Dave Staffel, the Special Forces officer in charge, gave the order to shoot, Sergeant Anderson fired a bullet into the man’s head, killing him. In June, Captain Staffel and Sergeant Anderson were charged with premeditated murder. On Tuesday, in a rare public examination of the rules that govern the actions of Special Operations troops in Afghanistan, a military hearing...