Last of 30,000 extra troops deployed in late 2009 have left Afghanistan , an official says . About 500 U.S. troops remain in Afghanistan . Green-on-blue attacks show there 's no easy way out . Obama has pledged to have most all coalition troops out by December .
Last of 30,000 extra troops deployed in late 2009 have left Afghanistan , an official says . About 500 U.S. troops remain in Afghanistan . Obama has pledged to have most all coalition troops out by December .