The broader questions about why Afghanistan finds itself at this juncture undermine attempts to justify the “war on terror” as it was waged in the country over two decades. During my more than three years in Kabul, between 2013 and 2016 (including as U.S. ambassador from 2014 to 2016), it became evident to me just how steep the challenges to U.S. strategy were. Although we were largely successful in eliminating al Qaeda in the country and reducing the threat of terrorist attacks in the United States, we failed in our approach to counterinsurgency, to Afghan politics, and to “nation building.” We underestimated the resiliency of the Taliban. And we misread the geopolitical realities of the region.