(Jim Huylebroek | The New York Times) Hoping to flee the country, people gather outside the airport in Kabul, Afghanistan on Friday, Aug. 20, 2021, as a military cargo plane takes off. Since sweeping into Kabul last weekend, the Taliban have moved swiftly to cement their control over Afghanistan, dispersing protests with force and hunting down opponents despite pledges of amnesty, according to witnesses and a security assessment prepared for the United Nations.