Ahem. Turns out it may have been largely the Brits’ fault:
President Hamid Karzai’s chief of staff on Thursday said that British authorities were responsible for bringing a Taliban impostor into the presidential palace and that foreigners should stay out of delicate negotiations with the Afghan insurgent group.
In an interview, Mohammad Umer Daudzai said that the British brought a man purporting to be Akhtar Mohammad Mansour, a senior Taliban leader, to meet Karzai in July or August but that an Afghan at the meeting knew “this is not the man.”
Afghan intelligence later determined that the visitor was actually a shopkeeper from the Pakistani city of Quetta, he said.
All in the finest British traditions, of course…