Joe Klein tries to get a handle on it. Klein dined with Richard Holbrooke just before he died:
Holbrooke believed tensions could not be reduced without a diplomatic solution. He wanted to cap his long career with a final haggle this one with the Taliban themselves, leading to a peace conference celebrating the 10th anniversary of the Bonn accord, which established the Karzai government in December 2001. He was at odds with Petraeus about that. The general was looking for something closer to a surrender than a negotiation from the Taliban, and his remains the default position in the Obama Administration. Holbrooke was also skeptical about the efficacy of maintaining a large U.S. force in Afghanistan, although he was curious about what sort of progress I'd find when I visited the Taliban heartland in December. (He collapsed before I could talk to him, on the morning I returned.) But Holbrooke and Petraeus did agree on one aspect of the war: cold storage. Both were convinced that there would never be real stability in Afghanistan until a strong agricultural economy returned. Having lost his faith in the Karzai administration, Holbrooke hoped a credible government could emerge from the bottom up, from local shuras like the one in Zhari that Eikenberry met with, from a rural populace that had moved on from poppies a funding source for both the Taliban and Karzai's friends to pomegranates and wheat.