Added 5/6: A review of a recent book about the Soviet withdrawal from Afghanistan in the late 80s. Parallels? Decide for yourself.
There is no good exit strategy available for the U.S./ISAF/NATO from Afghanistan, which should not be very surprising: there rarely are good options for withdrawal and extrication from this kind of conflict. The best outcome might be a negotiated peace settlement that brings elements of the Taliban into a kind of national unity government, but that prospect does not seem at all likely right now.
Pres. Obama has said that after 2014, the U.S. will remain only to help the Afghans with 'counterterrorism' and training. Eugene Robinson asks why the U.S. doesn't make that switch now instead of at the end of 2014. The official answer is that the extra time is needed for the Afghan security forces to gain more strength, though that is not exactly a comforting or perhaps even a convincing rationale or justification for continuing loss of life.
Two former State Dept. employees who worked in Afghanistan, writing in the March/April 2012 issue of Foreign Affairs, argue for leaving a sizeable number of U.S. civilian and military advisers in Afghanistan after 2014, adding that the advisers should 'rough it' and share the risks to which those they are advising will be exposed. Obama did not mention this approach explicitly in his speech from Bagram the other evening, but I wouldn't be surprised if an 'advisory strategy' is basically what ends up being adopted, regardless of who wins the November election here. "Advisers" would be a loose term covering both civilians and a military force, which David Ignatius thinks could number up to 20,000, though Obama mentioned no numbers in the speech. Ignatius believes this strategy makes sense, but here's a problem: what happens if, by the time 2024 rolls around, Afghanistan is still in turmoil and the 'counterterrorism' strategy or 'advisory' strategy (I think the differences between these are not all that significant) hasn't succeeded? Commit the force for another ten years? I don't think anyone would be happy with that.