Barnett Rubin:

Well, first, just to clarify, none of those things will be fully agreed until they are all fully agreed.

That is, even when the U.S. and Taliban reach an agreement in principle on the framework for the U.S. withdrawal and for counterterrorism measures, that — its implementation will still be conditional on the cease-fire and an agreement on a political resolution.

Now, the Taliban have refused to talk to the Afghan government thus far, but they have always said that they will talk to other Afghans, though without recognizing the government as such, once there's a plan in place for withdrawal of U.S. troops.

And, similarly, I think they have agreed in principle on a cease-fire. The question is about the timing. As they say, they claim they're fighting about — against the U.S. what they call occupation. They're reluctant to agree to a cease-fire until they see movement on that.

So I think there's some complicated issues about sequencing and coordination. And then the political settlement inside Afghanistan, of course, could be challenging. That will involve not just the Taliban and the Afghan government, but a broad cross-section of Afghan population, including women, civil society, all the various ethnic groups and so on.

And it's yet to be determined how that will be structured.