Last weekend's Nato summit in Chicago was mostly about how to get Nato troops out of Afghanistan without causing too much embarrassment to the Western governments that sent them, and a little bit about how to ensure that the Taleban don't take over again once the Western troops leave.
The timetable for Nato's withdrawal is now engraved in stone: All Western troops will be withdrawn from actual combat by the end of 2013, and they will all be out of the country by the end of 2014 (except the French, who will all leave by December of this year). This timetable will be adhered to no matter how the situation on the ground develops - or more likely, degrades - in the next two years. After that, it's entirely in the Afghans' hands.
There was some pretty rhetoric to soften this harsh fact: "As Afghans stand up, they will not stand alone," declared President Barack Obama. But alone is exactly where they will be, although Nato is promising to send the Afghan government $4 billion a year to enable its army to stand up to the Taleban. The Western alliance has finally accepted that if the foreign troops cannot defeat the Taleban in 11 years, they are most unlikely to do so in 13 or 15 years.
The Russians could have told them that. "Our soldiers are not to blame," General Sergei Akhromeyev told the Soviet Politburo in 1986. "They've fought incredibly bravely in adverse conditions. But to occupy towns and villages temporarily has little value in such a vast land where the insurgents can just disappear into the hills."
According to the Pentagon's own numbers, each American soldier in Afghanistan costs about $1 million a year. Pashtun teenagers, eager to show their worth fighting against the foreigners, can be had for about $200 a month each - and there is an almost inexhaustible supply of young Pashtun males. The war was unwinnable from the start.