the straight-line border that divided ethnic populations is the Durand Line, established in 1893 to separate British-controlled India from Afghanistan.
It separated Pashtun tribes on the North-West Frontier (now Khyber Pakhtunkhwa) from their counterparts in Afghanistan, creating lasting cultural, tribal, and political divisions.
The line is still a source of tension, as Afghanistan does not recognize the border as legitimate, and it continues to affect the safety and community structure of the tribes.