I've seen this movie three times now, and it's a favorite. Not because of the subject-matter because that itself is horrifying, but because of the underlying message. Did they 100% accurately portray military tactics and decisions--I'm not knowledgeable enough to comment on that. I do know I watched it with someone who's served two tours and he said that with the exception of a few things, they were fairly accurate for a Hollywood movie. Did they accurately portray the conflict in Nigeria? I know a little of what goes on in those countries because of friends who do work over there, but I also know that some of it has been exaggerated . . . at least in part for present day.
I believe they were trying to convey conflict that has and does exist in many countries around the world. It's not a movie meant to be "loved" or even to be in awe of.
There's a lot of internal conflict for the characters, and that is one of the most important aspects of the movie. The message is clear, powerful, and obvious, and that is the point. As for the superficial stuff, all of the actors are excellent in their roles, the photography is beautiful, the drama is powerful. It's Hollywood, so they're going to take some liberties, and that should be expected. There aren't overdone special effects that make no sense (sure, they're going to make things go boom). If you watch this movie with those things in mind, you just might be able to understand what they were trying to do (aside from just creating an action flick). It's not for the faint of heart or the overly critical, but in my opinion, it's worth watching.