Two years ago, the US government's position was that the Taliban would have to unequivocally renounce violence and end its links with Al Qaeda, before the Americans would be willing to talk. But this week, the US has agreed to revive moribund negotiations with the Taliban, in Doha, even though neither of those conditions has been met.
It is no coincidence that the US overture came just as nominal control over the security of Afghanistan was turned over to Afghans.
Nor is it a coincidence that the handover was marked by new Taliban bombs and attacks. The US is not going to be allowed to follow the cynical old doctrine for such situations: "Declare victory and get out."
That the Taliban can agree to talks and set off new bombs at the same time is no surprise, in part because "the Taliban" is a myth. Coordination among guerrilla groups is ragged at best, and tribal and regional disputes often divide them. There is no real hierarchy in the forces that have made the US occupation so bloody, and toyed with the "government" of Hamid Karzai - who yesterday said he will boycott the new talks unless his administration has a leading role.
Clearly the model of a modern state that serves most of the world well is not appropriate for Afghanistan, and so foreigners should not hope to impose their template. The Americans, like the Russians and the British before them, find in Afghanistan the graveyard of empire.
That is not to say that Afghanistan cannot be governed; confederations have held together well there at some periods; the Durrani empire, based mainly at Kabul, lasted almost 200 years until the 1860s.
The Americans and their allies stormed into Afghanistan after the attacks of September 11, 2001, to close Al Qaeda's camps. Now the US goal must be to support the growth of some kind of Afghan state that will not again serve as a cradle and haven for terrorists; although this is not a US precondition for talks, it will surely still be a prime American aim.
However Afghanistan is governed in future, the whole world - not just the western countries - has an interest in a country whose government takes its place in the world's councils, rather than being a disruptive outlier.
An Afghanistan that is neither a failed state nor a rogue state: that's a goal that almost everyone - including the great majority of Afghans - will surely support. For the Americans, and others, talking to spokesmen for some elements of the Taliban is clearly one step on the long and rocky road to that goal.