Is Iraq in a Civil War?

This post was started several days ago. Meanwhile the discussion of whether Iraq is in a civil war has only accelerated. Lehrer News Hour had a discussion last night. Both the Times and Post have pieces today on the issue. The Post in particular has some good points on the relation between language and reality: If you call it a "civil war", that might tell potential participants it's time to pick up weapons and fight. On the other hand, if you don't call it "civil war" you run the risk of losing credibility. (On that point, I'm reminded of Vietnam in February 68. The administration had been optimistic for years. When Tet came, they lost most of their credibility among the center. This was true even though the military would say that Tet was a defeat for the Viet Cong/North Vietnam. Lesson: Words matter, just as reality does.)

John Hinderaker at Powerline posts on Iraq statistics, arguing the situation is not as bad as the media says and does not constitute a civil war. (See also here.) His arguments have included the idea that the casualty rate is less than in the U.S. Civil War, that most of the country is peaceful except for Baghdad, and that the violent death rate in Bagdad is close to or only a small multiple of the murder rate in American cities at some times.

I'd make some counter arguments:
1 The Iraq population today is about 26.7 million; the US population in 1860 was 34.3 million. Over the course of the Civil War, the killed in action averaged 3,846 a month, the October Iraq figure was 3706. See this LSU site on the Civil War.
2 Lincoln in the Gettysburg Address famously said: "We draw deep comfort from the fact that in July of this year, the country was peaceful except for small areas around Vicksburg, Mississippi and Gettysburg, Pennsylvania."
3 Lawyer Hinderaker should realize violent deaths within a legal system, however much the criminal justice system was challenged in DC in the past, damage the social fabric much less vigilante justice than the sort of militia violence we see in Iraq.

An additional note: I bolded "killed" because it helps my argument. Most of the deaths in the Civil War were from disease, not bullets. Whether the appropriate comparison for Iraq is KIA or military deaths is debatable, but I'd lean to KIA.