KABUL, Afghanistan — Fleeing the encroaching front line in the embattled southern Helmand Province, Haji Abdul Qudus has moved his family many times this year, ending up at a rented home in Lashkar Gah, the provincial capital.

But his family of nine, and the thousands of others from across the province who have been displaced to the small bastion, fear for the worse: what if Lashkar Gah also falls?

“We don’t feel secure here,” Mr. Qudus said. “The Taliban are not far from the city.”

For months, a resurgent Taliban, which is making gains across several districts in Helmand, has been holed up in Lashkar Gah’s suburb of Babaji.

The embarrassing prospects of another urban center falling to the insurgents, after the northern city of Kunduz earlier this year, has drawn Afghan reinforcements as well as NATO troops back to Helmand to assist in the operations. The coalition forces also cannot afford the loss of Lashkar Gah for its symbolic value: Helmand was at the heart of President Obama’s surge of troops and resources, and there were more coalition casualties than any other Afghan province.