(L-R) US President Barack Obama, Defense Secretary Chuck Hagel and Joint Chiefs Chairman Gen. Martin Dempsey pay their respects at the Pentagon Memorial to mark the 12th anniversary of the 9/11 attacks on the South Lawn of the White House in Washington, DC, on September 11, 2013. AFP PHOTO/Jewel Samad AFP PHOTO / Jewel Samad (Photo credit should read JEWEL SAMAD/AFP/Getty Images)