It’s just not true that, as Biden put it, “our reasons for remaining in Afghanistan are becoming increasingly unclear.” The mission — preventing the creation of a Taliban-sponsored haven for jihadists — remains as clear as it was 20 years ago, and requires a continued, though modest, U.S. presence. Our involvement in Afghanistan was never about building a utopia at the war-torn geopolitical crossroads of Central Asia, despite U.S. efforts to support the development of democracy in the country and over-optimism at times about its prospects. Our involvement was always principally about preventing the reemergence of a terrorist threat capable of killing Americans on U.S. soil. This isn’t merely a theoretical concern. Al-Qaeda reconstituted itself in Pakistan in the late 2000s, and we were able to hit the terror group from Afghanistan (including in the bin Laden raid). And ISIS attempted to establish a base in eastern Afghanistan several years ago. Crucially, what Biden didn’t mention in his speech is how much the U.S. operation has changed over time. The war fought today is entirely different from the conflict in which Americans engaged in regular battles with Taliban forces.