It's always fun when you get to hear a speech that you can say with a fair amount of certainty will be played for tragic irony in movies a generation from now (I imagine it playing on an iPhone as Forrest Gump III kisses a girl dressed like Miley Cyrus as he graduates from the University of Phoenix). Which is not to say it's the wrong decision--I certainly wouldn't know--just that it is so clearly the only tenable one that the best anyone can hope for is understanding of that fact. There's no longer any real criteria for success and there may never have been--democracy! O!--but eight years later it seems silly to imagine we can just up and leave without consequences for ourselves let alone the men (and especially women) of Afghanistan and Pakistan. But it's equally silly to imagine that bullets in the service of a corrupt government will make anything better.
Which is why we get to again have speeches about exiting that somehow announce major troop escalations. Afghanistan is not Vietnam but it is not Iraq either. The "success" of "the surge" there would seemingly be irrelevant in this discussion but there's no denying it's attractive to ignore those distinctions. On the one hand you have the possibility of some protracted withdrawal that would attempt, pointlessly, not to lead to the fall of the government and regional instability and on the other you have the dream of just a few more months with a few more troops and...
It's easy to see the good that might be done. It's easy to see how no one else is willing to take responsibility for the world and feel like you have to. It's easy to see the odds of Islamabad's collapse following Kabul's and have your hand forced by terrifying hypotheticals.
Who knows. To paraphrase Kushner's Homebody/Kabul, "In Afghanistan, the choices are frequently narrow."