General John W ''Mick'' Nicholson, commander of NATO's Resolute Support Mission and US Forces-Afghanistan, listens to Afghan President Ashraf Ghani during a joint press conference with US Defence Secretary Ashton Carter at the Presidential Palace in Kabul on July 12, 2016. US Defence Secretary Ashton Carter reiterated Washington's support for "courageous" Afghan security forces July 12, days after the United States and NATO pledged to keep thousands of troops in the troubled country. / AFP PHOTO / SHAH MARAISHAH MARAI/AFP/Getty Images