Here is an article that has a different take on the level of violence in Iraq. At least some of the killing may be vigilantes working toward a stable government, by killing those who refuse to stop terrorizing.
That force is not, as often claimed, civil war as such, or even religious war.
It is something with which we have become quite familiar in Latin America: vigilanteism on a massive scale—murder squads and desaparacidos—the force of civil society itself in extremis.
When there is a significant fraction of the population that will not join in political compromise, whether because of ideological idealism, addiction to supernatural power, or the passion for revenge, civil society is faced with a diabolical paradox.
It wishes to form legal and political institutions that are transparent, correctable by debate, and under the control of the people (with protections for minorities), where people can make good money in the marketplace and raise families in peace. But the reality is that even after all possible compromises have been offered to the refuseniks, civil society is faced with a small but absolutely hostile minority that will be content with nothing but total victory.
What can civil society do? The only solution is the disappearance of that implacable moiety.
There are, from the point of view of Iraq's nascent civil society, some thousands of people who, in the Texas phrase, need killing. Who is going to do it?
In the absence of government intervention, the answer is: ordinary people. Basically the killers are posses of self-organized vigilantes, who know their local area, who know who the bombers are, and who the bombers' relatives are. The posses are expert in distinguishing those people who might be fair political enemies from those who will go on striking, like a snake, even when cut in two.
But, as Socrates knew, this dark archetypal crime must be hidden. The American authorities in Baghdad are not saying much about it because the vigilantes are doing their work for them, with infinitely greater precision and expertise. The Iraqi government is not doing or saying much about it either, because it would lose legitimacy if it cooperated with the death squads, and sabotage its own interests if it tried (probably unsuccessfully, anyway) to stop them; but it obviously cannot admit that this inaction is its policy. The U.S. Republican Press cannot say anything about it because it would imply in an election year that it approved of the death squads. The Democratic Press cannot give the vital information—that most of the victims probably deserve their fate—because that would imply that the Iraqis have finally started to do what they were expected to do all along, that is, clean up their own house.