This is a fundamental question of about the tactics employed by our military. Frankly, I don't understand the strategic logic behind what they're doing. It seems this drive to retake the Iraqi cities must be based entirely on emotion (revenge) or be some sort of idiotic attempt to save face. I'll make my case below.
Here's my take on the situation:
To begin with, we already controlled these cities at one time. Then there was a rapid uprising which either caused our troops to be overrun and forced to withdraw or made it so they lost practical control of the city (ie; hiding in their base, while the streets are a free fire zone).
Obviously given the superior technology, firepower and training(? maybe?) of our forces, it's no surprise that they'll be able to push back into the cities. Insurgent forces can't keep them out, especially when they're reinforced by air power.
However, after they fight back into the city, what do they do then? How do they maintain control over the city once they're inside. What's stopping the insurgents from falling back, letting them pass and immediately setting up behind them.
That's the real issue: we don't have the manpower to hold the cities-- not really. We can keep fighting our way in as a coordinated force, but without leaving a squad on every street corner, there's no way for us to actually maintain hold on the cities. Whenever our troops move on to a new location, there's nothing keeping the insurgents from regrouping and taking the area back again. And even supposing we disrupt the insurgency enough that there is a lull while they regroup, they've already kicked us out once and there's no reason why they can't do it again.
At this point I really feel we have lost control of Iraq. In order to effectively hold the cities we'd have to divide our troops so we could effectively cover all the ground. But if we just put our troops on every street corner we lose a great deal of our tactical advantage. The troops would just be sitting ducks waiting to get picked off. I believe the casualties/casualty ratio in that situation would be highly unacceptable. Meanwhile if we don't do that, I don't see how we can gain effective control the cities again.
It seems to me the whole military command must be hoping that this is just a flare up and that it will die down after a few days. Because if not, I just don't see how they expect to prevail. A better strategy might be to just withdraw from the cities and negotiate with the leadership that emerges in each location.
Right now, it seems to me, the question isn't whether to cut and run or tough it out. It's whether we want to stay there, suffering casualties and accomplishing nothing, or whether we want to get out of there, save lives and accomplish no less. We never were prepared for a true occupation, and could not truly be prepared
In order to prevail we'd need a massive army like China's, rather than the small, skilled force we have. We'd also have to be willing to suffer a high number of casualties--more than the public will accept. All of which has been true all along, and why our choice to invade was so incredibly foolish!