The fostering of jihadist militancy is not the end of the Durand Line's consequences. It also went on to foster the "Pashtunistan" movement — a political campaign to reunite the Pashtuns on either side of the border. After Pakistani independence, the movement was endorsed by the Afghan government, which encouraged a mob to torch the Pakistani embassy in Kabul in 1955. Through the 1950s, '60s and '70s, Afghanistan and Pakistan subsisted in mutual hostility, and in that bipolar Cold War world, Afghanistan was drawn little by little into the Soviet orbit. Thus, the Durand Line helped to create the conditions for the Soviet invasion, the beginning of the cycle of violence that persists to this day.

Pathans adhere to the code of "Pashtunwali", the "way of the Pathan". Chief among its aspects is the need for badal, revenge, the source of bloody tribal vendettas that can last generations. Badal wreaks its malign curse against foreigners, too. It is no coincidence that the very Waziristan villages that were bombed by the RAF in the 1930s in an attempt to curb jihadist revolt proved readiest to take in al-Qaeda fighters fleeing Afghanistan in 2001, and later became intractable strongholds in a Waziristan Taliban "mini-state". The Haqqani network is among the Afghan Taliban's deadliest elements, but its headquarters lie in North Waziristan, on the Pakistani side of the Durand Line. 

To adapt Marx's dictum, on the northwest frontier history tends to repeat itself, the first time as tragedy, the second time not as farce but deeper tragedy. Nato's prospects of achieving victory in the present conflict do not look encouraging, and its use of a similar mix of force and bribery is no more likely to bring lasting success than it did its predecessors, the empires of the British and the Soviets. Perhaps a better understanding of the region's history might help.  As good a place to start as any is with a singular British bureaucrat, floating down the Kabul River on his bullock skins, glorying in his telegram from Queen Victoria in November 1893.