In the dusty badlands along its disputed border with Afghanistan, Pakistan is carving out a massive trench to keep out separatists, smugglers and militants in an attempt to bring order to a lawless, tribal region.
But like the Berlin Wall or Israel's West Bank barrier, the planned 300-mile trench is giving physical form to a border that locals have long seen as artificial, dividing families and crippling trade. And it is adding to simmering tensions between Afghanistan and Pakistan, U.S. allies which have long accused each other of turning a blind eye to insurgents.
The trench runs along part of the Durand Line, named for British diplomat Mortimer Durand, who drew the now internationally recognized border in an agreement with Afghan ruler Abdur Raham Khan in 1893. But the modern Afghan government has never accepted the border, and neither have the mainly tribal communities that straddle it. They are accustomed to moving back and forth freely and in some cases own land on both sides.