The Pearl Harbor surprise attack occurred 71 years ago today. It is an example of the kind of intelligence failure we would most like to be able to prevent in the future: a violent and severe attack against a critical American target, in a case when there is a pretty good set of reasons to expect an attack sooner or later. It is not, to use Donald Rumsfeld's old terminology, an unknown unknown: we must simply accept that we cannot predict those. It is an example of a known unknown.
Something similar is going on in Egypt today. Media coverage of the protests seems to be under the impression that there are three sides: the Muslim Brotherhood, the Army, and the protesters in the streets. In fact there are only two sides, because there are only two powers: the Muslim Brotherhood and the Army.
As recently as a couple of days ago, the Army was tacitly encouraging the protests -- sometimes more than tacitly, according to reports. This was about showing Mursi and the MB that their thugs weren't really capable of standing up to a full-scale revolt. Mursi has been very successful at out-maneuvering the Army politically, and has managed to win power and control at their expense several times.
It was clear that a deal had been struck in principle when the tanks surrounded the palace to protect it, and Mursi. Now the outlines of that deal have become clear.
Once the powers have finished dividing the authority between themselves in a way that both find acceptable, the protests won't be useful anymore. Then it will be time for a "whiff of grapeshot."
If I were an Egyptian protester, I would realize that now was the time to get off the streets. There is about to be an example made. The only question is exactly when.