CORVALLIS, Ore. (AP) - Mike Duncan rolled up his pant leg to reveal the scars on his left leg - scars where bullets had entered his thigh and knee while he was serving in Afghanistan in 2009.

Duncan was at the end of his nine-month tour and set to fly home when his Special Forces team learned of an American soldier who had walked off his post and was missing. Instead of returning to the United States as planned, the men were sent to a remote town south of Kabul to gather intelligence on the soldier's whereabouts.

While patrolling the town, the team was ambushed by Taliban fighters. Duncan took...