Ok, so this will probably still mean a prolonged period of indecision as regards a U.S. troop increase, but The New York Times has a great and very detailed
“„Mr. Karzai’s apparent capitulation came after an all-out push by Obama administration officials and their European allies. But even if Mr. Karzai ends his strong resistance to a runoff, that would not resolve the country’s political crisis, officials say. It would be difficult to hold a new election quickly, as the Afghan winter approaches, and delaying the selection of a new government until the spring could allow the Taliban to make further gains across the country.
“„As a result, some Obama administration officials, who say a pending decision on whether to increase troop levels in the country depends partly on resolving the election outcome, now argue that they should push Mr. Karzai and Mr. Abdullah to form a coalition government to avoid a runoff altogether.
“„A second senior administration official said some American diplomats and allies were pressing for a negotiated settlement, but were trying not to be too involved for fear of looking like they are interfering.
“„“If you jam it, it has no legitimacy and you’re further behind,” the official said. So instead, the administration is “creating conditions” so that the Afghans come to see a negotiated deal as in their own interests. “If they want an election, an election it will be,” the official said.