Gary Farber at Amygdala has an informative piece on the situation in Afghanistan, focusing on three crucial questions:
Can the government in Kabul become one that most Afghans regard as legitimate?
That is the antepenultimate question, rather than which military forces or strategy should be used.
The penultimate question is: if so, can we help the government in Kabul become that legitimate government?
The ultimate question for America and NATO is: if so, how high a price is too high a price for us to pay to help the government in Kabul become that legitimate government?