David Broder's formula for failure:
From his op-ed
Corrupt and inefficient as [the people running Kabul] may be, they are less of a threat than the Taliban would be. And so we must prop them up.
Especially since he also writes:
[While American troops are in Afghanistan] the Taliban can continue to exploit public frustration with the dysfunctional Afghan government, recruiting new fighters perhaps as fast as McChrystal can woo people away.