Here's a possible solution--i.e., what I would do if I were the man in charge:
1. Send a message, via all possible media, to those in Iraq. Tell them to pay close attention to their portion of the sky at a specific time. Make sure that it's dark out, as in the dead of night.
2. Notify our NATO allies, and all others in the region.
3. At the specified time, light off an extremely high-altitude nuclear weapon--say, about 100,000 feet up, in the megaton range.
4. Warn the Iraqis that ANY more atrocities against Americans or foreign personnel WILL result in the immediate detonation of one of those (somewhat smaller than that, but don't let them know) devices against the city or region where the attack took place.
5. During the preparation phase for all of this, get every inch of footage that was taken of the mutilation and display of bodies. Obtain still photographs of all possible who were cheering or participating. Distribute those photos to combat units.
6. As a part of the announcement, notify the city of Fallujah that they have one hour to give those participants over to American authorities. If they are handed over, fine. Give them a fair trial.
7. For those who are not handed over forthwith, conduct a house-to-house, room-to-room search of the city. Place a cordon around the city prior to this happening. Anyone attempting to escape other than through established checkpoints will be shot on sight. No quarter.
8. When any who participated in the atrocities are found, they will be taken to the street, shot, and left there. No quarter.
If they want to play, fine! But, from now on, we should make the rules.