This is the most honest and detailed discussion on the topic we've heard to this point. Obama says he would hope to have all U.S. troops out of Iraq by 2013, but Clinton and Edwards won't make the same promise. Edwards guesses 3,500 to 5,000 troops will be necessary to protect the American embassy in Baghdad and do humanitarian work. Obama says American soldiers will be needed in Iraq to guard U.S. bases, do counter-terrorism work, and protect Iraqi civilians. It's Edwards here who is arguing with Clinton about their differences on Iraq. He claims she would continue combat operations, she says that like him, she wants to redeploy the vast majority of troops. Bill Richardson takes the unrealistic stance of not leaving "any troop behind." --Dana Goldstein
