Why Taliban are so strong in Afghanistan

Nato has invested hundreds of billions of dollars over the past 10 years trying to raise a modern army for Afghanistan and to rebuild the country's infrastructure.

But if a leaked classified report prepared by the alliance is to believed, all this will go to waste soon after foreign combat forces withdraw in 2014.

The latest in a series of leaks suggests that Nato is much more worried about the course of the war than it lets on in public.

Nato has tried to play down the importance of the report by calling it a "compilation of opinions expressed by Taliban detainees", but it highlights many failures in the decade-long war in Afghanistan.

"Senior Taliban representatives... maintain residences in the immediate vicinity of ISI headquarters”

The harsh reality is that an increasing number of Afghans are turning to the Taliban, having grown mistrustful of Nato and Afghan forces