What we need to do is get the answer to one question: WHO is providing the funding to these guys?
Once that question is answered, then the mission becomes the elimination of their funding sources. Without funding, the Taliban will wither away. We need to cut off funding for the radical madrassahs that create and indoctrinate the Taliban. We need to cut off the funding that enables them to obtain weapons and supplies.
The problem with that is that it leads directly to a set of people in Saudi and elsewhere, and no US administration wants to touch them.
The question has a simple answer. For the most part, we are! The Taliban gets most of its money from protection money paid to it by the U.S. funded Karzai government and the projest of International Organizations (usually funded by the U.S). See here.