>> to ensure the success of democracy, maliki, a shiite, needed to heal the powerful schism between shiites and sunnis in iraq, but he never did. so when asked by the shiite abusers to fight against isis, the sunni soldiers and the iraqi army simply said no. >> for many sunnis, they looked at iranian-backed regime in baghdad and they looked at isis and some of them made the disastrous calculation that isis was the lesser of two evils. >> the last american soldier left the country in 2011, after the u.s. could not reach agreement with maliki to maintain a military presence. >> the question that we ask today when people look back at that decision is what would we have done with 10,000 u.s. troops? would they have enforced security? and frankly would we have wanted