It is still on balance worth the United States hanging on in Afghanistan, for a variety of reasons.
There is no chance of military victory over the Taliban. Nor, without a U.S. commitment to withdraw its troops and accept a major share of power for the Taliban, does there seem any serious chance of a peace settlement (the brief truce to mark a religious festival notwithstanding). Nor, with 100 percent of the Afghan security budget and around 60 percent of the civilian budget funded by the United States and other outside donors, is there any chance of the Afghan state standing on its own feet.