Fall of Kabul, Taliban Overthrow 'Not a Foregone Conclusion,' Milley Says Secretary of Defense Lloyd J. Austin III and Chairman of the Joint Chiefs of Staff Army Gen. Mark A. Milley hold a joint press briefing from the Pentagon, Washington, D.C., May 6, 2021. (DoD/U.S. Air Force Staff Sgt. Jack Sanders) 6 May 2021 As the U.S. military's withdrawal from Afghanistan gathers steam, Defense Secretary Lloyd Austin and Chairman of the Joint Chiefs Gen. Mark Milley expressed cautious optimism Thursday about the Afghan government's ability to stand firm against the Taliban. This month, the U.S. military officially began pulling its last few thousand troops out of Afghanistan, to meet President Joe Biden's Sept. 11 deadline for bringing the two decade-old war to a close.