"If American forces step back before Baghdad is secure, the Iraqi government would be overrun by extremists on all sides. We could expect an epic battle between Shia extremists backed by Iran, and Sunni extremists aided by al Qaeda and supporters of the old regime. A contagion of violence could spill out across the country – and in time the entire region could be drawn into the conflict."
Just like what the leftist and the media did in Vietnam!