By August 2021, most of Afghanistan has fallen under the control of the Taliban, including the capital of Kabul on August 15. The last time the Taliban controlled Afghanistan, it was the location of Al Qaeda training bases and leadership that led to the 9/11 attacks on the United States and the subsequent invasion of Afghanistan by the North Atlantic Treaty Organization (NATO). With the fall of Afghanistan to the Taliban, there is increased concern that it will be used as a base for terrorist attacks.