Thousands of U.S. troops are now heading home from Iraq every week. By New Year's Eve, the 45,000 who were there on Oct. 21 when President Obama announced their final pullout, will be down to zero. So what does Iraq's near-term future look like once all the U.S. troops have come home? The Obama Administration has said it had no choice but to pull out of Iraq by year's end after the Iraqi parliament made it clear it would not grant U.S. troops immunity from Iraqi law for any alleged wrongdoing. Was that a reason -- or an excuse -- to come home? John Nagl, of the Center for a New American Security, and I debate the pluses and minuses of the pullout plan with Lawrence Korb, a Reagan-era Pentagon official now at the Center for American Progress, and Michael O'Hanlon, a military expert at the Brookings Institution.