Bradley Cooper with "American Sniper" director Clint Eastwood. (Photo: Warner Brothers)

That sensibility was important in bringing art out of the otherwise barren and unpopular landscape of the Iraq War, according to Hall.  "Iraq wasn't a pretty war," he said. "It's ass-hot; you're thirsty and dirty. Clint found beauty in the truth of that."

The movie crew also underwrote the movie's realism by involving veterans in the production, most notably Navy SEAL vet Kevin Lace who started out as a stuntman and wound up playing himself and the wounded vets who appear in the target practice scene toward the end.

"American Sniper" had a limited run in theaters during the holidays, and the box office results were very encouraging and quelled studio execs' fears surrounding the track record of movies about the Iraq War. (Even the Oscar-winning "The Hurt Locker" didn't do that well, money-wise.)

But Hall feels that the journey he's been on with "American Sniper" – shaped by having to deal with the loss of his friend Chris Kyle – created something distinct and more universal than others have managed on the topic.

"'American Sniper' started as a war movie," he said. "But it wound up being a movie about war."

Watch WATM's exclusive one-on-one interview with "American Sniper" screenwriter Jason Hall:

More on this topic: 'American Sniper' Is A Must-See Film That Brilliantly Honors The Memory Of Chris Kyle

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