Well, as an American strategist, that would depends on the aims and strategy of the US involvement in Afghanistan. Which aim is unknown or unclear to most of us, so I cannot say what the appropriate decision is from an "American insider" point of view.
From my POV (as someone who desires a peaceful South Asia with secular or near-secular democratic states with EU-like borders; and who would like to see the Taliban and their "confrontation-conquest-Paknationalist-Jihadist faction" mentors brought under adult supervision), its a no-brainer. You pull the trigger.