Anatol Lieven in the New York Review of Books:
The United States and its allies today find themselves in a position in Afghanistan similar to that of the Soviet Union in the late 1980s, after Mikhail Gorbachev decided on military withdrawal by a fixed deadline. They are in a race against the clock to build up a regime and army that will survive their withdrawal, while either seeking a peace agreement with the leaders of the insurgent forces or splitting off their more moderate, pragmatic, and mercenary elements and making an agreement with them. The Soviets succeeded at least partially in some of these objectives, while failing utterly to achieve a peace settlement.
To date, that is just about true of the West as well; and while international support for the US position is much stronger than it was for the Soviets, our Afghan allies are much weaker and more fissiparous than theirs. Our Taliban enemies have been much more worn down militarily than the Afghan Mujahideen were by the Soviets during the late 1980s. But the Taliban and their allies draw on the same deep traditions of Islamist resistance to foreign “occupation” among the Pashtuns of Afghanistan and Pakistan as did some of the Mujahideen groups that fought against the Soviet occupation. (While Pashtuns are the largest ethnic group in Afghanistan, making up perhaps 40 percent of the population, they also make up about 15 percent of the Pakistani population and are concentrated along the Afghan border.) The Taliban have, moreover, comparatively safe bases in Pakistan to which they can withdraw. They will remain a very serious force.
More here.