History gives us two models for dealing with Afghanistan. The Korean model requires us to keep troops in the country indefinitely in order to maintain a stalemate; the Vietnam precedent is to negotiate a face-saving settlement and then get out as quickly as possible. Which will Trump choose?
It is clear at this point that he prefers the Vietnam model. It will lead to the demise of the current Afghan government and Taliban rule at some point in time. Trump will undoubtedly attempt to structure the deal so that he gets the maximum political benefit before the election, and only runs the risk of looking like the man who lost Afghanistan afterwards. If it occurs on his watch, he will blame Obama, Pakistan, and anyone else who happens to be around, and then we will move on.