Short Answer: It's 'OK'. Not bad; not great – just OK. It's certainly worth watching for free via Prime as it portrays an actual event in U.S. military/history.
The acting for the main protagonist and antagonist is great, along with several of the minor character roles. Other minor roles – some playing the crazed, blood lust role – are a little over the top in my opinion, but, they all do a good job creating stress and tension for the plot. The movie likely needed another hour to provide a better metamorphosis from green, naive soldiers into hardened killers due to combat stress, but because of time constraints of any 1.5 – 2 hour movie, this lacking is understandable.
You can't help but feel sorry for the young soldier faced with such a moral predicament.
Miscellaneous: I wouldn't call this an anti-military propaganda piece, but that's debatable. I do wish movies like this would provide examples of how ruthless, barbaric and evil some of the Middle-Eastern combatants are. Be it ISIS, Taliban, Al-Qaeda, etc. etc., they routinely torture, kill and maim innocents – including children – without hesitation if it suits their goals (or blood lust). These events are well documented if anyone chose to look. While these U.S. soldiers crossed the proverbial “line” and deserved punishment, it doesn't compare to the atrocities committed by jihadists worldwide on a daily basis. (And no, their actions/behavior is not “the U.S.'s fault” as jihad was waged far before the U.S. was even a country. Alas, that's another topic.)
Should the comparison justify or excuse these U.S. soldiers' behavior? No. Americans and the U.S. is better than that, in more ways than one; but as the old saying goes, “War is hell.” There are many truths in that phrase.
In all wars, throughout history, there are individual actors on all sides of every conflict which do very bad things, including things which go beyond “acceptable” warfare. That's a tough pill to swallow for those that are privileged enough to never pick up a weapon and step into battle; it's even a tough pill for soldiers too.
I'll leave it with this thought: for someone to use this rare but horrible incident as a means to generalize every U.S. soldier is a mark of ignorance, naivete and gullibility. Dare I say stupidity? If we can use this one example to tarnish the entire U.S. and it's military, then why can't we use one (out of many) examples of Jihadists killing innocents in order to tarnish them, their lifestyle and their culture too?