The Moore, Kerry and Fonda types who are critical of this movie (or American warriors in general) missed the brief scene early in the movie where the sniper, as a young boy, was taught by his father about sheep, wolves and sheepdogs ...
https://netwar.wordpress.com/2007/08/30/sheep-wolves-and-sheepdogs/
The concept is lost on them.
Except that Jane Fonda said the movie was excellent
excellent link...