Very recent developments in Iraq are very bad, but there is probably a glimmer of hope in what news I've seen: the fact that Iraqis are stunned at the violence of the last few days probably means we won't see this continuously. There may be further outbreaks of this sort or worse, but hopefully they'll be infrequent.
I think now is the time to ask a tough question: at what point should we say Iraq has crossed the line from "sectarian violence" into "civil war"? What are the criteria that separate the two? On first reflection, a civil war seems to require (at least) two sides with competing claims to legitimate rule over a certain territory, but this seems unlikely in a time and place where the nation state looks very different than it did in (for example) 19th C America. Neither terrorist organizations nor fundamentalist Islamists--and I'm told there's an overlap there--seem to be interested in collecting taxes or providing police service. So let's come up with a broader definition of civil war, in order to fully reflect the violence of the situation if and when the time comes.
I propose this: we can call it a civil war when bombings and disruptions such as this are not resolved in any way before the next one occurs, so that the events run together enough to be considered one large event. To be more precise, this will occur when the period between major violent events is shorter than the news cycle. There will be at least two objections to this definition. First, that the length of a news cycle is undefined. I agree, but I don't mind leaving this as a subjective definition, open to reasonable interpretations. As a rule of thumb, let's remember that the Cheney shotgun story, which was drawn out longer than necessary because of a sloppy media strategy, lasted a little under a week. The second objection will be that this defines the term on the basis of our Western perception of events rather than that of the Iraqis, who would obviously be most affected by this hypothetical war. I don't really have a problem with this. The closer you get to the ground, the less it matters what you call it. If you die as a result of sectarian violence, you're just as dead as if you die in a civil war, and your family is just as devestated. It's only as you move away from the events that names become important. If we have a good idea what Civil War is, we'll have a better idea when to admit failure and change strategies.
That is, if anyone can think up something good.