I have an old book on dog training (I'll try to find it and post a citation) with a chapter on the predator dog. The author points out that if you have a dog that is killing your neighbor's cats, sheep, and chickens, you have two choices: either a painful and forceful training regimen to break it of the habit, or kill it. The training regimen he recommends goes like this: You start by getting a chicken and an electric fence charger. You tie the chicken on an insulated surface with one lead to the fence charger and attach the other one to ground. Any dog that bites the chicken is going to get a mouthful of voltage.
But the author stresses that you can't just do this a couple of times and then let it go. You first have to get the dog to internalize the consequences of biting the chicken. You put the dog in a small pen with the electric chicken and you keep it there for a month. It's not the one or two painful shocks that break the dog of attacking chickens, it's the month of sitting in the pen, constantly, over and over, making the decision not to bite the chicken.
That's what the marines are doing in Fallujah. Sure, they could have gone in and mopped up the town in a few days, but what effect would that have had? A brief day of terror, a few months of grating anger, and the people of are back on the attack. A couple of painful shocks isn't going to break a life-long habit. Instead, the marines declared a cease-fire for the purpose, I believe, of giving them a reason to impose martial law for an extended period. Every day, the citizens of Fallujah are reminded that they are helpless against the Americans. They are at the mercy of their enemy and their enemy is showing mercy. Yet they live in constant danger, their movements are restricted, they are living on rationed food and water, and none of this would be necessary if not for the rebels. And every moment of every day, they have the occupiers there to attack and they choose not to attack them. The marines are conditioning the predators into peaceful citizens.
So although Captain Ed makes some good points, he doesn't take into consideration the predator-dog factor. I agree that a swift victory would have intimidated the resistance a bit more, but it was more important to alter the habits of Fallujah.
Thanks to Back of the Envelope for the link.