For most of Abdul Manan’s life, the border dividing Afghanistan and Pakistan was little more than a line on a map. Like generations of men before him, Mr. Manan, 55, commuted every day from his mud-brick home on the Pakistan side to the wheat field his family had cultivated for decades in Afghanistan. His four sons crossed the border with him, transporting electronics and groceries from markets on one side to homes on the other.

It was a journey shared by tens of thousands of residents in the Pakistani town of Chaman, the site of the last official border crossing where people could pass through using only their national identity card from Pakistan. Then, in October, the gates slammed shut.

Pakistani officials say the restrictions are a necessary security measure — though most of the travel originates on their side of the border — as the country has grappled with a resurgence of cross-border militant violence since the Taliban seized power in Afghanistan in 2021.

For the first time since the border was drawn over a century ago, the Pakistani authorities are requiring residents to show a passport and visa before crossing — paperwork that virtually none of them have, they say.

The rules have upended their daily lives. Small traders say they have been effectively locked out of their shops, where their goods rot and bills for shuttered stores mount. Farmers have missed out on wheat harvests, leaving them unable to feed their families, they say. Porters, who once earned up to $3.50 a day by transporting goods like electrical items and groceries on their backs or on hand trolleys, have lost their only source of income.