There are opinions about whether the violence in Iraq can be called a civil war or not. From the Iraqi perspective on the street, it is moot. It is violence and death, pure and simple, that is happening on their streets and to people they know. From a geopolitical perspective, it is important to define whether it is truly civil war occurring in Iraq or not because if it is civil war, the USA will be pushed by the Democrats to assume the war is lost and a pullout will occur of US forces. If you are one of Al Quaida and its Shura council or Sadr's militias, this is what you want because it opens the greatest opportunity for you to take over Iraq not caring that all of you would turn Iraq into a smoldering cinder fighting among yourselves. For the bulk of the Iraqis, regardless of your sentiments about foreign occupation, this will be a change for the worse.
For comparison, the Lebanese Civil War, almost next door, can be used as a benchmark. In that war, about 150,000 people died, multiples of that injured, multiples of that displaced. Even without the ratio of less than 4 million compared to over 26 million in Iraq taken into account, the level of violence in Iraq still pales to what happens in a real civil war. You had Black Saturday in which 600 people died in a single day, and that wasn't the worst of the Lebanese War. You had two known massacres of 1,000 people each not to mention the 2,000 Palestinians dead when Syria decided to invade on the side of the Maronites. When civil war occurs in Iraq, you will have refugee displacement in the tens to hundreds of times of what is happening now. You will have armies fighting to take territory from each other with the USA being unable to stop them even in face-to-face combat. When a civil war truly occurs in Iraq, there will be no debate or doubt from anybody. So, from a geopolitical sense, there isn't a civil war yet in Iraq. The potential is there as Iran continues to supply Sadr's militias and Syria continues to supply Al Quaida and its Sunni allies of convenience. But in order to keep the far left seeking to dominate the Democrats at bay, we can't say that a civil war is truly occurring now.