It's a movie, for one; retard.
2; it's called holding a position. When you in hostile territory, you keep your firearm LOADED and up.

Fuck is he supposed to be doing in a war zone? 

The point of he is an aggressor is moot. Anyone in his shoes would pull the trigger, you yourself said you would.

What are you eve. Arguing? This isn't about the child, or the movie or shooting people.

This is all about you. Your entire argument is your morality. No one fucking cares.