The Moral and Story-Arc of 'Fury' [SPOILERS]

I really enjoyed Brad Pitt's WWII movie 'Fury' which came out a couple months ago.

Here's my take on it. Brad Pitt's character ('WarDaddy') was a seasoned, talented professional soldier and leader of his men. But in the bloody circumstances on the front lines he had lost his humanity, and even as he struggled to maintain his civilized habits, we see that the war has corrupted and tainted him. So WarDaddy had to die at the end. There was no other possible conclusion.

The most moving part of the movie is when WarDaddy takes the already-surrendered Kraut who is waving around pictures of his wife and kids, throws the pics on the ground and careful forces Norman the newbie to point the revolver at him and shoot him point-blank. The reason is supposedly to get Norman to be able to pull the trigger later when he'd have to, but it's such a heinous war-crime in that I personally could not forgive him. He was a tainted character - not as evil as the SS monsters he was hunting, but still perhaps no longer fit for civilian life.

So in the end in one of the last major skirmishes of the war, the blood finally catches up with him and takes him down. It's a tragedy because we sense that he's a good man who has struggled to do the right thing in a terrible bloody place. But he'd become what he'd despised and there was no saving him. His death was the only way for story to make sense as a tragedy. Otherwise the movie would have been a very strange, unbalanced story.

Thoughts anyone?