American Sniper has become a huge success for Clint Eastwood and Bradley Cooper. Breaking any number of records, including biggest January box-office opening in US history, the film seems to have struck a chord with American audiences.

With the film on release in Ireland, it remains to be seen if it will enjoy a similar success with our own audiences.

Screenwriter Jason Hall talked to us about his own experiences with Chris Kyle, Clint Eastwood and why the film isn't as pro-America as you might think.

(SPOILERS)

E: To begin with, how did you come to write the screenplay? 

Jason Hall: I heard about Chris' story in 2010, that he was the most lethal sniper in US history and I thought it might be a good story. I went down to Texas to meet him. You ask yourself certain questions about someone when you hear that about them; about how the amount of lives he was asked to take and what kind of man he was and what it took out of him.  

I saw a great turmoil there that was hard to look at, quite honestly. I didn't know if there was a story there, I felt like I had been dropped into the middle of something that was incomplete. I was fortunate enough to stick around for the night. In the morning, when I saw him with his wife and family, I recognised that there was somebody else there underneath.

He'd certainly been someone before and maybe he had a chance to somebody else again. Looking at his wife, I saw this marriage that had been pushed through this war and seemed to be reeling, this woman who raised his kids and in that struggle, I felt there was a movie.

E: What kind involvement did Clint Eastwood have in the script? Were you on set with him?

Jason Hall: We cut some of the script for budgetary reasons, but [Eastwood] doesn't meddle too much with the script. He did bring a certain musicality to stuff. He's a musician, he has a way of sweeping through things. Economy's the wrong word, musicality is the word for it. He's beautifully efficient and he can express things with a look or a glance. It's very cinematic and old-school and it's quite effective.

E: The film is marked by its fantastic action sequences. How did you get that action into the script?

Jason Hall: I read every book I could about the Iraq War. There's a few books that directly approach the tactics there and I talked to Chris as much as I could. He certainly revealed stuff in the book, vignettes of things he went through, and we explored things that he chose not to in the book - the enemy sniper, for example. He was mentioned in the book, but Chris didn't want to go into it too much because he didn't want to glorify this guy because he shot his friend.

He talked about him more over the phone with me and there was a lot of this scope-on-scope battles that he had with these enemy snipers. He believed that anything outside a certain distance was this Moustapha guy. In a movie, it's easier to see who they're fighting during a scope and in a real battle, it's a little more difficult.

I've written a few action movies in my day, I've only had a few made but I've written about twenty movies - so I've had practice doing character dramas and action movies.

E: Did Chris' murder impact on the script or was it finished before he died?

Jason Hall: I worked on it pretty much every day with him, calling him up to ask questions. I called him on Thursday to say that I was turning in the first draft and on Saturday, he was murdered. We put the thing on hold, I went to the funeral and reconnected his wife and his SEAL team-mates. The script changed quite a bit after that.

His wife called me about five days after the funeral and told me that if I was going to do this, you're going to have to do this right because this is a part of how her kids would remember their father. She talked about Chris' personality, who he was. There was a different perspective than I got in the book.

Y'know, what a lot of people don't realise is that he wrote this book [American Sniper] when he was less than a year home from war. He dictated this book across a barstool to somebody with a tape recorder and just told them stories, with someone coming in to brush it up and turn into a book.

You're getting the voice of a warrior who wasn't totally home yet. He still had his armour on and he expressed a certain zeal about the war and romanticises it in a way. That wasn't the man she married, that was the man he became a decade of war and it wasn't the man he was when he was murdered.

E: You mention that Chris romanticised his experiences. One of the criticisms levelled against the film is that it's jingoistic and pro-war.

Jason Hall: I think that criticism is narrow-minded, honestly. This is a story about a man who wants to protect and serve his country and because of the type of man he is and this God-given skill he has, he's used by his government to do a certain thing. For that service, he pays dearly on a personal level. Few of us can imagine the level of spiritual and mental anguish of having to take this many lives. And while he did it well and willingly to save his fellow soldiers, he paid dearly for it.

To say this is a jingoistic or pro-war movie is narrow-minded in that what we're witnessing, from the very first shot, is a man who's humanity is being shaved away. His very person is taken from him with every shot and every tour he served. The accumulative effect diminishes his life in a way that none of us will experience if we haven't got to war.

To me, it's a picture of what these men went through who chose to go to war. We sent two million of these men away and this is their story. This is what many of them bring home to us, this kind of anguish that we'll never know or understand what they're living with.

This is about their sacrifice. To say that's jingoistic in the way that he's interpreted it and paid for it and the mental anguish he goes through - I don't know how you can romanticise this as a pro-military movie. It's a movie about a man's sacrifice and the ghosts he brings home and how he finds a way to live with them.

E: What are you working on next?

Jason Hall: I'm working on a film about Rasputin, that's also for Warners, with Leonardo DiCaprio. He's attached to play the role, we'll see how that shakes out.

E: He's got the beard for it, doesn't he?

Jason Hall: He does, doesn't he? He just needs a bit of dirt under his nails!