America’s “forever war” in Afghanistan began only weeks after the Sept. 11 attacks and lasted just short of 20 years, ending in the chaos of Aug. 15, 2021, when the capital, Kabul, fell once again to the Taliban. 美国在阿富汗的“永久战争”始于9·11袭击仅数周后，持续近20年，最终在2021年…