While American officials say the withdrawal matches the latest counterinsurgency doctrine’s emphasis on protecting Afghan civilians, Afghan officials worry that the shift of troops amounts to an abandonment of territory where multiple insurgent groups are well established, an area that Afghans fear they may not be ready to defend on their own.

And it is an emotional issue for American troops, who fear that their service and sacrifices could be squandered. At least 103 American soldiers have died in or near the valley’s maze of steep gullies and soaring peaks, according to a count by The New York Times, and many times more have been wounded, often severely…

The reorganization, which follows the complete Afghan and American withdrawals from isolated outposts in nearby Nuristan Province and the Korangal Valley, runs the risk of providing the Taliban with an opportunity to claim success and raises questions about the latest strategy guiding the war.

American officials say their logic is simple and compelling: the valley consumed resources disproportionate with its importance; those forces could be deployed in other areas; and there are not enough troops to win decisively in the Pech Valley in any case.