arma virumque cano (et alia)
Won't happen. Too many real Mercuns want to win even if it takes another 10 or 20.
No one could ever "win" in Afghanistan. Not even the Afghans. Read the real history. I'm sure you have, but on a positive note, I believe that Obama has been talking to Francois Hollande and the American position is going to change rapidly because of the pro active policies of Hollande regarding Afghanistan. He has "enabled" Obama to speed up the American disengagement.