America had a chance to maintain a modest, forwardly deployed presence, in perhaps the most pivotal center of global terrorism, by keeping its proverbial finger in the dike of Central and South Asian militant jihadism. Equally important, it had a chance to make good on promises of a better life—or at least protection from the worst possible life—for tens of millions of Afghans who put their faith and trust in the United States.

In other words, America had a chance to show its adversaries and allies alike that the United States could tackle very difficult challenges in the world, imperfectly if need be, while upholding its beacon of values at the same time. That all came to an end with Twitter celebrations by Islamist militants seizing Bagram Air Base, and with scenes of human beings literally clinging to American aircraft as they lifted off for the last time from Kabul airport.

It would be one thing if all of this hurt and sacrifice brought an end to the “forever war.” But in many ways, it is now beginning anew.

Stuart Gottlieb is an international affairs professor at Columbia University’s School of International and Public Affairs, where he teaches U.S. foreign policy and counterterrorism. He formerly served as a foreign policy adviser and speechwriter in the U.S. Senate (1999-2003).

Image: Reuters