What makes anyone think the Taliban is going to agree to this? Last I checked they were very "my way or get beheaded".
The Taliban will agree with this as means to an end. The end, of course, is something like the previous poster suggests.
Why have we been in Afghanistan so long? That's a good question. Ron Paul suggested in 2007 that we should "just leave"; I can't see the fault of that reasoning, all things considered.
The only thing I can say about this is that such a proposal is closer to what Trump suggested in his campaign than in traditional Neocon logic. That part is, perhaps, an acceptable consolation prize of a sort. Afghanistan is one of the biggest wastes of time, money, and lives I can think of.