Withdrawing early will destabilize the security of Afghanistan and bring power back to tribal Taliban leaders. The U.S. military should withdraw on its current timeline in 2014 and hand over security of the country to its leaders. Otherwise, the U.S. military will be there indefinitely. The war in Afghanistan has gone on for more than a decade. Another few months won't matter.
No, the US should not withdraw from Afghanistan sooner, because the country still is not stable. Leaving now would be an almost certain return to harboring the terrorists that caused September 11. As unfortunate as it is, the United States needs to commit troops until the job is complete, so that there will not be more terrorism.