KABUL, Afghanistan — For months, the secret talks unfolding between Taliban and Afghan leaders to end the war appeared to be showing promise, if only because of the appearance of a certain insurgent leader at one end of the table: Mullah Akhtar Muhammad Mansour, one of the most senior commanders in the Taliban movement.
But now, it turns out, Mr. Mansour was apparently not Mr. Mansour at all. In an episode that could have been lifted from a spy novel, United States and Afghan officials now say the Afghan man was an impostor, and high-level discussions conducted with the assistance of NATO appear to have achieved little.
“It’s not him,” said a Western diplomat in Kabul intimately involved in the discussions. “And we gave him a lot of money.”