Gen. David H. Petraeus, commander of International Security Assistance Force and Commander of U.S. Forces Afghanistan, shakes hands with 2nd Stryker Cavalry Regiment Trooper, Staff Sgt. Shawn Purdy of Bluefield W.Va. Purdy was one of four soldiers Petraeus reenlisted while visiting Forward Operating Base Lagman in the Zabul province of Afghanistan Jan. 17.