Islamic warriors might not be the best phrase to use. I'm thinking of some other titles to hand out. Even amongst their own kinfolks...if this were to get out...shooting a woman in the back...makes you look like a utter fool. I'd find the best punishment possible for these guys...laying in a anthill for a couple of hours might be appropriate for them.
I think we are all missing the point.
In this tit-for-tat situation, the point is to offend our sensibilities as greatly as 'we' offended the muslim's sensibilities. The pope 'insulted' their religion by insulting their religious leader. They picked a nun to signify catholicism, but they want us to feel the same kind of outrage they felt. To provoke that emotion in us, they killed a defenseless woman. They knew that would outrage us. And it has. THAT was the point, to outrage us so that we would feel what they feel.
How does one resolve such a thing?