A Soldier provides cover as another Soldier performs first aid on a simulated casualty during a training scenario at the Naval Weapons Station Yorktown, Va., during a counter improvised explosive device training course, June 13, 2013. Soldiers spent three days learning about different types of explosive devices, how to identify them and what to do if they encounter one. (U.S. Air Force photo by Staff Sgt. Wesley Farnsworth / Released)