The base was not much to behold when the American soldiers arrived in Kunduz in 2010. Nestled atop a vast plateau, it was little more than a collection of stucco buildings with chipping paint, a small airstrip on one side, a graveyard of rusting Soviet vehicles on the other. And everywhere was the Afghan dust, so fine it would puff like dry mountain snow with every step.

In the months to follow, the Americans greatly expanded the base. Seabees, members of the Navy’s construction unit, used heavy equipment to build walls from containers of dirt that encircled an area large enough to hold a second airstrip.

A small city of yellow, air-conditioned tents, with a basketball court and a chapel, rose in the field of dust. So did a sprawling maintenance bay for the armada of armored trucks.

The soldiers of the First Battalion, 87th Infantry out of Fort Drum, N.Y., could never quite fathom the reason behind the expansion, and by 2013 American forces were being withdrawn from the province.