There are two things to remember here:
1. Our troops will continue to need to maintain iron fire discipline in the face of continued provocation. Iraqi civilians didn't do this; Qaeda did. The good thing is that our men will not take this out on anyone around them; they are infinitely better than that.
2. This was a mistake by Qaeda; like the Malmedy massacre-this will point to the need to every American soldier and Marine in the field to fight to the death. Paradoxically, our men will internalize something similar to the old bushi-do code that made it so hard for Japanese troops to surrender during WWII. It was my understanding that Americans have fought to the death in this war anyway, given the remorseless nature of our enemy. No one wants to be beheaded on home video. This was stupid payback by Qaeda for al-Zarqawi's killing, and all it has done is to increase the determination of every individual Marine and infantryman not to be taken alive.
Armies that are staffed by noncoms don't make these mistakes. Qaeda isn't; and it's stupid things like this that show the difference between gangsters and trained infantry.
Be Seeing You,
Chris