Generation Kill vs the Swedish marines
I was in the Swedish marines for 15 months. I was a sergeant, the same as Brad Colbert is in Generation Kill. I did it for myself, because I was 19 and I wanted a challenge. I knew that I wouldn't be shipped off to Afghanistan and have to shoot people out there. It's very different when you enrol in the States because you know that a couple of months from now you might actually go out and be shot at. But it definitely helped me in terms of the structure of it, the banter between the guys, how you address your officers, how you address your peers, the gear, the weapons.  In terms of making it authentic, we had a couple of real marines from First Reconnaissance with us who were in the book. It's a true story: we didn't want to Hollywood-ise it, fictionalise it, throw in a girl and a love story. We wanted it to be real and we didn't want it to have a beginning, a middle and an end. We wanted it to be five weeks in what these guys are going through out there. It's not like the show ends and the conflict is over. We made it for all those soldiers over there because you don't really see what's happening on a daily basis, what the soldiers are going through and what kind of baggage they come home with. So it was just important to make it right for these guys to go to their families, "Watch this, because this is pretty much what we went through out there."

Modelling for Hickey Freeman vs Zoolander
I'd never done a commercial or an ad before in life, not even in Sweden when I was working there for many years. It just felt right. [Hickey Freeman] called and said Annie Liebovitz, who's one of the best photographers in the world, was going to do it, so it was an opportunity to work with her. We had a couple of meetings and we said no first. Like I said, I'd never done it before so I was very hesitant. But then we met a couple of times and the way they wanted it to be sounded very classy and not too promotional. I really liked the way it turned out, I think the shots are great and I'm very happy that I did it. It was an opportunity to work with a phenomenal photographer.

Lady Gaga vs Rihanna
They were very different experiences. I worked with Lady Gaga for a day on a video shoot. It was crazy; we had a lot of fun. I had a great time. [Filming Battleship] is a different experience because Rihanna, we're out there together for a couple of months. This is her first movie but she's great, she's really really good in it and her working… She's got a crazyschedule. She's really diligent and I'm impressed. We would work and then she'd fly to LA to perform at the MTV Music Awards and then fly back red eye, land, go straight to set, work all day. No complaints, nothing. She's really solid.

Tall vs small
My height can be a problem. A lot of directors and photographers are sometimes not happy because I'm pretty tall and especially if I work with short actors the difference can be pretty massive. [Laughs] That's definitely happened before. We use apple boxes for the other actors so they get up a bit.

Being naked on screen vs that cover shoot for Rolling Stone
Why do I "love being naked"? [Laughs] Because I was born that way? I didn't write the scripts but I don't mind it if it makes sense. It's about being comfortable and if it makes sense story-wise. The only time it can get awkward is if you feel exploited, like, "Why am I standing here naked?" and I've never felt that. There's always a reason for it on the show and it's always at great moments: fun, crazy scenes. So I really don't mind at all. The Rolling Stone cover just happened on the day. We showed up and we shot very PG-13 with our clothes on for basically the whole day, like six or seven hours. Then towards the end the photographer said, "I have this, these shots are beautiful and the magazine is going to be happy with them but I'd like to try something if you guys are game." He explained it and it was just one of those things in the moment where we all looked at each other, we'd spent all day with the photographer, we felt comfortable with him, we knew that he was great and the atmosphere was right and we were like, "Fuck it, let's do it." No one thought that the magazine would go for it. They want to sell at Walmart. We thought this was going to be too offensive. But I guess they did. [Laughs] I'm glad they did! I liked it a lot. It was definitely more interesting than the safe version…