Nearly twenty years after the U.S. military began operations against the Taliban in Afghanistan, President Joseph R. Biden reported on August 31, 2021, that the last U.S. combat troops had departed the country. Biden announced on April 14, 2021, that the United States would withdraw combat troops from Afghanistan before the twenty-year anniversary of September 11, 2001, and NATO member states decided to depart the country simultaneously. The withdrawal followed an early 2020 deal between the Taliban and the Trump administration, which conditioned the pullout on Taliban agreement not to harbor terrorists that target the United States and its allies. Over the course of a week and a half in mid-August, the Taliban captured most of Afghanistan's provincial capitals, entering Kabul on August 15. The Afghan government collapsed, and President Ashraf Ghani fled the country. Through the end of August, the United States and other countries conducted a major airlift operation to evacuate their nationals and Afghans considered at risk of Taliban reprisals, though many were left behind amid risks of renewed civil war and humanitarian crisis.