Two thousand Iraqis were killed in March alone. The attack on Sadrist forces, insisted upon by the US, was a huge fiasco, and the subsequent "peace" between Maliki and Sadr was brokered by America’s bete noir, Qassam Sulaymani, head of the Quds Brigade of the Iranian National Guard. The US had to stand by watching impotently. The cat is out of the bag. Iran doesn’t have the weapons but it has the greater influence.
If the US wants to stay in Iraq it will be as junior partner with the Iranians, paying the Sunnis to keep quiet. It will cost a fortune and achieve nothing. The propaganda from the subservient U.S media is being pumped out at high volume, but it cannot hide the failure of the whole enterprise. But then only the under-educated ever thought it was anything else.