The reaction to my last post was a lot stronger than I expected, and as such, I think it's worth clarifying my thoughts a bit. Contra a few of the commenters, I am not asking progressives to uncritically accept whatever decision President Obama makes. But I am asking progressives to look at Obama's decision in the context of everything he's said and done, and then ask themselves whether it is fair to accuse him of betraying them. It's not, as I pointed out, because he didn't.
Moreover, I think progressives are fooling themselves if they think that Obama could both withdraw from Afghanistan and pursue his domestic agenda in full. Fifty percent of Americans support keeping troops in Afghanistan, with a solid majority of independents supporting this position. There also seems to be a solid consensus in favor of escalation among the professional commentariat. And among Democratic policy-makers, there aren't many who are opposed to committing further resources to Afghanistan. The simple fact is that withdrawing from Afghanistan, even if it's the right policy, would invite a torrent of criticism: Republicans would immediately attack the administration as "defeatist," and the Beltway media would welcome the opportunity to perpetuate the myth that Democrats are hostile to the military and "afraid" of American power. Withdrawal will yield significant political fallout, and it's not clear to me that the Obama administration has enough momentum to move through that fallout without taking a real hit to its domestic agenda. Indeed, I don't think it's a stretch to say that escalating in Afghanistan is the price the administration pays for having a broad domestic agenda.
This is something of a banal point, but it's worth making nonetheless: There are costs and trade-offs to everything the administration does, and if progressives want the administration to take a more counter-establishment approach to foreign policy, they must be prepared to sacrifice a portion of their domestic priorities. You can't do both.