U.S. President Barack Obama (2nd R), Vice President Joe Biden (2nd L), Joint Chiefs Chairman Gen. Joseph Dunford (1st L) and Defense Secretary Ash Carter (1st R) attend an Armed Forces Full Honor Farewell Ceremony for the president at Joint Base Myer-Henderson in Washington D.C., the United States on Jan. 4, 2017. (Xinhua/Yin Bogu)