Or is it about time? That all depends, of course, on what you think the U.S. mission in Afghanistan -- now a decade old -- actually is. We have booted the Taliban from power, and recently killed Osama bin Laden, who orchestrated the 9/11 attacks from inside Afghanistan in a sanctuary the Taliban provided. Now President Obama has begun ordering U.S. troops home, with Afghanistan's government shaky, corruption endemic and the Afghan security forces fledgling, at best. Stephen Biddle, an Afghanistan expert at the Council on Foreign Relations, and Brian Katulis, a senior fellow at the Center for American Progress, debate the issue with John Nagl, president of the Center for a New American Security, and your Battleland scribe.