There are no shortage of controversies regarding the American War in Afghanistan. Across 2009 and 2010, a group of soldiers calling themselves The Kill Team murdered at least three innocent unarmed Afghan civilians. The story of “The Maywand District Killings” was documented in Dan Krauss’ 2013 non-fiction account, The Kill Team.

Six years later, Krauss returns to the true story with a new feature film based on his documentary, also called The Kill Team. Starring Nat Wolff and Alexander Skarsgård as soldiers whose moral compasses point in different directions, The Kill Team offers a punchier and more emotional take on this uncomfortable portrait of American youth, armed and abroad.

While promoting the release of The Kill Team, actor Nat Wolff spoke to Screen Rant about his work on the film, from getting to spend time with the real life inspiration for his character to the influence of movies like Serpico on this 21st century whistle blower story.

The Kill Team is out now in theaters and VOD.

I talked to Dan about this, but one of my favorite movies when I was a kid was Serpico.

That’s what Dan said! Was playing this kind of whistle blower role something that attracted you to this movie?

That’s one of my favorite movies!

It’s kind of like discovering your moral compass, like a coming of age story, even.

Definitely. I actually watched Serpico about three weeks before I started shooting. I guess the main difference between Serpico and this movie is that Serpico is a man. You know? As much as my character is doing his best to be moral and ethical, he’s still a kid. You watch these guys in the documentary and they have acne on their face. Some of their voices sound like they haven’t even fully dropped. They’re kids! It makes you have a different kind of empathy for the fact that they’re a little bit more confused than somebody like Serpico, who has so much conviction.

Yeah, it’s so easy to have power, to be someone who carries guns for a living, and to exert that for self gain. And it can seem so hard to have power and not exert it on those who don’t have it.

Yeah, it’s like a really dark coming of age movie. I love Serpico so much, especially because that character can almost be annoying, do you know what I mean? Doing the right thing can be annoying!

Did you and your co-star, Alexander Skarsgård develop any kind of rivalry or relationship on set based on your characters? How did you bond?

Definitely, 100%.

There’s something about these movies, whistle blower movies, particularly with the military angle, where it can seem almost dangerous as an artist. Did you ever feel like people might take the movie the wrong way and think you’re ant-military? Was there any fear or concern about your image?

I think there was a lot of bonding with some of the guys. Skarsgård and I have become really close in shooting. I brought him to his first Hanukkah!

Did you get to meet Adam Winfield?

There wasn’t for me. I think there’s nobody who is more legitimately educated on the subject matter than Dan. He made the documentary, he knows all the guys. And we were all clear about the fact that the majority of soldiers are, of course, good and true blue. Shining a light on this story is important because it’s not just about the army or the military. It’s about humanity. In all different circles, there’s toxic masculinity, manipulation, peer pressure, and it’s really hard to do the right thing. I responded more to those greater universal themes.

Was there anything in particular you took from him for your performance?

I ended up going and staying at his house in Seattle. We spent three days together. It was really helpful in terms of understanding this guy who went through this traumatic experience but… He’s kind of an inexpressive person, but that doesn’t mean he’s not a very sensitive person.

Was there anything you learned about the military while you were making the movie, outside of the particular subject matter of the film?

It was clear it had been harrowing. He gave me some insights and things that I promised not to say. But there were definitely things that I got from him that I carried through the whole movie.

I was also talking to Dan about Casualties of War.

I thought I already had respect for the people in the military, for the people who served. After just playing war, which is .00001% of the psychological toll I assume and imagine war is, I have even more respect for them. I have a lot of empathy for… Especially for Adam, but for all the guys in the squad who were manipulated. And I also see the horror of it, too.

Yes, and Michael J. Fox. It was a case where I saw Back to the Future and was like, “I love this guy! What else has he been in?” And I was not ready.

Oh yeah, with Sean Penn.

I’m always interested in how an actor prepares. Some like to get ready by watching movies with similar themes. How do you build a character, particularly one who is based on a real person?

That movie is so f***** up.

Was that your salve, your way of unwinding after carrying that weight with you?

I think one of the main things with this character is that he was going through so much, it took such a psychological toll on him, that he had a hard time expressing it. He had no avenues to speak. So one of the things with this character is, he was bottling a lot of the anxiety every day. Me, as Nat, wanted to scream and cry and be a baby, you know? Which is probably how I would react. But the character had his idea of what it means to be noble, what it means to be a man. And that meant bottling it up. I would go home sick to my stomach because I was bottling all this toxic anxiety. Some of the preparation was meeting with Adam, that was a big deal. It was the first time I worked with a new acting teacher, who really helped me find and personalize this character, and pushed me to go as deep as I could. And then, yeah, I watched Serpico, I watched The Deer Hunter, I watched about 45 minutes of Casualties of War, which I had already seen a bunch of times. A lot of times, a month or two months before doing the movie, I’ll watch a lot of thematically similar movies, but during the shoot, I just watch Bojack Horseman and Family Guy.

Although Bojack Horseman might not have been the best choice!

Exactly. It was too heavy. I needed to decompress.

More: 18 War Movies That Aren’t Focused On The Fighting

I know, it’s so dark! It was really heavy.

The Kill Team is out now in theaters and VOD.