In the past decade, Ben Stiller has gone from being a cult comic sensation to an MTV staple to a global box office superstar known worldwide, a very busy one at that, which is why it’s very rare to see him doing interviews outside of the normal movie junkets once or twice a year.

This summer, Stiller’s fourth film as a director, Tropic Thunder, will be released by DreamWorks/Paramount. It co-stars Jack Black and Robert Downey Jr. as a group of actors making a Vietnam War movie who are dropped off in the middle of the jungle by the film’s crazed director (Steve Coogan) as part of their training, but wind up in the middle of an actual warzone without them realizing that they’re not still shooting the movie. It’s a fluid mix of war film and comedy that pays homage to serious war films like Apocalypse Now and Platoon while taking digs at the “Rambo” movies along the way.

Stiller and Downey Jr. showed up in Las Vegas during ShoWest last week to debut the trailer and a couple clips of the comedy and the following day, Stiller was nice enough to take some more time out of his busy schedule–his appearance at ShoWest took place n the middle of a series of California test screenings–to sit down with a select group of journalists from online websites to talk about the movie and other upcoming projects including the sequel Night at the Museum: Escape From the Smithsonian.

ComingSoon.net: It’s been seven years since you directed a movie. Why was now the time go back and what was it about this idea that made you want to direct again?

Ben Stiller: Well, this movie I’ve been working on for a while. I had the idea for the movie like twenty years ago when I was doing “Empire of the Sun” in 1987 because at that time, that’s when all these Vietnam movies were being made and my friends and I were going on auditions for these Vietnam movies and my friends were getting them and going away to fake boot camps. It seemed like there was a time when all actors were going away to fake boot camp and talking about these incredible experiences that they had and how it really changed their lives and there was something there that seemed funny to me. Maybe it was because I wasn’t getting parts in those movies, but I was like, “Oh, wow. You’re going off and getting all of that. What about people who actually go to war?” The actors were like owning this experience as if it was like this real and incredible experience. I’m sure that it was a great experience, but it wasn’t like actually going to real boot camp.

So that was percolating in my head and I thought maybe I’d do a short or a sketch about actors who go away and do Vietnam films and come back and are forgotten, trying to parallel the veteran’s experiences. That didn’t seem funny at all. (laughter) So I put that away. Then the idea came that it might be cool to have a movie about a bunch of actors that get stuck out in the jungle on a movie and are caught in this real situation, so literally, for the last ten years I worked on a first act of it, about ten years ago, and then Justin [Theroux] came on about eight years ago. I said, “Come on, lets work this.” Then we brought on Etan Cohen about four years ago, so literally over the last ten years we’ve been working on the script in different and various forms. I would go away for a few weeks on vacation or something and work on it.

CS: So how much military training was involved?

Stiller: So minimal. I got in touch with Dale Dye. He’s like THE guy for training. He was in “Platoon,” and he’s the guy who does all the boot camps. He did “Saving Private Ryan” and is like the military advisor on all the movies. Dale and I emailed a bit maybe about six or seven years ago when I was telling him about the idea. He gave me a lot of feedback on experiences that he had taking actors out into the jungle and a lot of that stuff comes out of what he told me, like going on “Platoon” and taking the guys out on an overnight and Oliver Stone telling him to scare the shit out of the actors. So when it got down to doing the movie, Dale was going to take us out. I said, “We’ve got to do a boot camp.” We were going to do like this two-day intensive boot camp in Hawaii when the guys got there for rehearsal. I said that we had to do it. Then as we got closer and closer to shooting the schedule started filling up and Downey was doing “Iron Man.” He was going to get there a couple days beforehand and it was finally getting so tight because of all the prep that we were doing for the movie that my producer came up to me one day and said, “Alright, here’s the choice. We either do the two day boot camp or we can do a cast dinner on Saturday night.” I was like, “Lets just go for the cast dinner. That’ll be much more fun.” Also, Dale got a job directing this other TV show and so he couldn’t be there. I think that when Dale went away, the pressure was off because he’s so imposing and he’s so tough. We just bailed on it, honestly. But we did have his guys there and they showed us how to shoot the guns and stuff. It really felt that the license was just to be able to have fun with this since we were just actors trying to be soldiers, so we could be bad at it.

CS: Did you go looking for some outrageous stories from actors about being on a war set and stuff like that?

Stiller: Yeah, and like I said, I got a lot of stuff from Dale and then also friends of mine who were in “Hamburger Hill” and I go way back with them. They’d talk about being back in the Philippines there doing that movie and how they really did have to do these crazy two and three week boot camps and were just stuck in really horrible hotels. There’s also the stories about the guys who didn’t show up at the boot camps, the stars that didn’t go to the boot camps because apparently that’s a real thing that happens on some war movies. So it was an amalgamation of all those stories, input from friends and then just figuring out what we wanted to do for the story in the movie.

CS: Was this always going to be an R-rated movie?

Stiller: It became evident while we were writing the script, and there’s been so much emphasis in the last couple of years, I think, placed on R versus PG-13 and when we were coming up with the movie we weren’t thinking about the rating. It did become evident that there was language in the movie. If you were going to do a war movie this is a part of it. We were writing the first scenes, which you haven’t seen yet, but they’re out in the opening of the movie which is the movie within the movie and so it’s this sort of hot LZ and they’re trying to do an extract mission and coming in with the choppers to pull the guys out and there’s all this over the top dialogue that is just like so many motherf**king and f**ks in there. You can’t not do it and do one of these movies, be in that genre, so that’s what it came out of. Then when we realized that we were stuck with it being an R that we should then at least have fun with it since we’re going to have to be an R.

CS: And there aren’t lot of decapitations and “I’ll suck your d**k” in a PG-13 movie.

Stiller: Yeah, exactly, but I’m working on that. I think we need to open it up. (laughter) What’s crazy is that I just watched “Beowulf” and maybe I watched the unrated DVD or something, but that was a PG-13 movie and limbs were being torn off and blood was splattering, so it’s a very slippery slope. There’s no clear guidelines. I guess if you have two “f**ks” in a movie, it’s an R, but there aren’t any real clear guidelines on what they say you can and can’t do. It’s all up to interpretation.

CS: You’ve worked with a lot of these guys before. Can you talk about casting some of them and then the new people you cast as well?

Stiller: For Lazarus, for Downey’s part, it was really important that’s like the biggest thing, because it was like who are you going to get that’s an actor that everyone respects because it had to be the real deal. It had to be a guy who would actually believe is this incredible award-winning actor and also be really funny and also be able to do that character because he’s in character for the whole movie. That was a really short list. I didn’t really know Robert before and we ran into each other actually in Hawaii the Christmas before we were shooting. We have a mutual friend that introduced us and it was like we hit it off and I thought, “Wow. I should ask this guy.” You get a little shy sometimes when you have a friendship and then you also have a script and you don’t want it to be like, “Hey, we met in Hawaii. Here’s my script. I think you’re awesome, man.” I just decided to do it because I thought he would be so uniquely suited to it and that he would get it. He really loved the script and then we did a table reading.

Jack [Black] was always in my mind, but never in a million years did I think that Jack would do it. I just thought that he would have his own thing going on and this was an ensemble thing and I didn’t know what his thing would be, but he was always that guy to me, and when he read the script and liked it I was like, “Oh, my God. Jack wants to do it and Robert Downey wants to do it.” Then everybody else started to fall in and for Sandusky, the Jay Baruchel part, that was a really tough role too, because that guy sort of has to be the straight guy through the movie, but also have a really good sense of humor. He came in and auditioned and he just had this take on the character where he was actually doing a character. He just saw the actor guy doing the character for the movie. He had that whole take on it as opposed to just playing the straight guy. A lot of really good actors came in for that role, but he just had a really great comic sensibility. I hadn’t seen him in “Knocked Up” or anything. I’d seen him in “Million Dollar Baby” and that’s all I knew of his work. But he’s awesome and so committed and he’s so funny. A lot of the stuff that he does in the movie, which you’ll see, is that he’s sort of a movie geek in the movie and he talks a lot. A lot of the times I would have him talking on the set and I’d say, “Okay, lets film that.” He would talk about this whole HD versus Blu-ray DVD’s and what the difference is and the pixel rates and he’d go on these rants while they’re trekking in the jungle. He drives everybody crazy because he just keeps talking and talking and so he gave us a lot of material.

CS: You also filmed an accompanying mockumentary while filming “Tropic Thunder.” Can you talk about that too?

Stiller: Well, just in keeping in the vein with the movies we were sort of in the genre of and paying homage to–I don’t like to say satirizing because it’s not really satire, it’s not parody, it’s like whatever the movie is within itself. All the elements are in the other films and this movie exists because of those other movies were made. In “Apocalypse Now” [Francis Ford] Coppola’s wife did “Hearts of Darkness” so we thought that might be fun to do, a documentary about the making of the movie within the reality of the movie and Justin Theroux who wrote the script with me and Etan Cohen, he took control of this thing and wrote this fake documentary about the director who, as you saw what happened to him in that scene last night, basically went crazy. He took these actors out into the jungle and never returned. It’s like, “What happened and what’s the story there?” So we filmed that sort of concurrently and Justin directed that and wrote it and did interviews with the actors while we were shooting. I’m not sure what we’re going to do with it. I think it’s going to come out a little bit before the movie comes out, maybe online in segments. It’ll definitely be on the DVD. It might be on a fake sort of History Channel show or something like that, but it was basically having fun with that. It was actually really cool because we were able to use elements of that for the movie also in terms of like footage that he shot and the interviews. Steve Coogan is like a huge part of that.

CS: When you’re working with so many comedians do think ahead of time about what you’ll have for the DVD?

Stiller: For sure, and especially I think on this movie. First of all, the first cut of the movie was like three and a half hours and I walked away going, “Wow, I know there’s like twenty minutes that I can cut ” When I first saw it “But I don’t know after that.” The first time I put up it in front of people I was like, “Oh, my God, I can take that out and that out and that out.” But there was really a lot of stuff that we couldn’t use and so I feel like in terms of some sort of director’s cut or even like alternate scenes or something there’s a lot of stuff there that I’m excited for people to see and there’s a lot of stuff that even in the mockumentary, stuff we couldn’t use even within that, where like Downey  he’s just off the charts in this movie, in my opinion. He just does an incredible job. I feel like he’s sort of breaking new ground in terms of comedic acting and the reality level and also just how funny he is. He went off and did a whole thing in the mockumentary about his character that was sort of like a substory about what happens to his characters and going crazy while playing the part. It’s just insane. It was too insane even for the mockumentary so I don’t know what’s going to happen with it. It definitely needs to come out after people have seen the movie because otherwise people will be like, “What the hell is this?” (*Note: You can find out what Downey Jr. did as a footnote at the end of this piece.)

So we have a lot of material there in terms of that stuff. The war sequences we had to cut down and there was a lot of stuff there. Oh, and the trailers too. We did these fake trailers before the movie that sort of setup the characters. The character that I play in the movie has done this really bad movie called “Simple Jack” where he played a mentally retarded man who talks to animals. My character did think he was going to win an Oscar and it’s then panned across the board and is a huge disaster for him, so he’s coming off of that movie going into “Tropic Thunder” and needs to sort of regain his place in the world. We did a trailer for “Simple Jack” and you see part of it in the movie, but there’s a full trailer for that Justin is actually in too and my wife is in it and Mickey Rooney is in it. It’s awesome. So that’ll be probably a part of the DVD, too.

CS: When you’re on the set of a movie within a movie like this, is it hard to tracking of everything going on and knowing which is which?

Stiller: There were definitely times when it was a little bit silly because in that opening scene when we break the fourth wall of the movie my hands are blown off and I’m doing this emotional scene and the director is yelling “Cut!” So you’re doing this scene where you’re filming the director and this crew of like a hundred people filming our scene and my hands are strapped behind my back and I have fake arms. I realized when my hands were strapped behind my back how much you use your hands when you’re directing. You need them to say, “Do this and do that.” It just becomes a part of it and so when you have to direct with your hands behind your back and you’re trying to tell them to cut, because also the director is saying, “No, no, keep it rolling ” because the scene is about keeping it rolling, it all became just silly. I would have to say, “No, no, no. Stop filming for real. This is Ben talking.”

CS: Are you surprised that in this day and age you were able to keep Robert’s look in the film under wraps and then premiere it on your own terms?

Stiller: Yeah, I don’t really know how that works in this world these days because I feel like it’s basically that if you’re off the radar with something and people don’t know about it I guess if it’s not a “Star Wars” movie or something where people know it’s coming maybe they’re not looking for it as much. I think that we were all very clear that we didn’t want to put it out there until we had a context for people because they would see it and be like, “What the hell is that?” So, yeah, I guess so. There are so many places where things can get leaked or emailed or put out there and I guess that we got lucky in that way, that nobody broke trust or anything. I think also because the movie was sort of under the radar for a long time that no one really knew about it and it wasn’t announced as a big tentpole thing and we were just sort of making the movie.

CS: There were some secrets about the film that got out like Tom Cruise’s cameo in the film. Were you disappointed that that was leaked out because it could’ve been a really great surprise?

Stiller: I guess so, but I don’t know how you keep that stuff today under wraps if people are coming after it. With Tom, people are watching him so much and I think that happened because people are always just following him around. I don’t personally care though, because I feel like what he does in the movie is so insanely funny and is just so great. I think that people are going to be in for a great surprise. I think the fact that he’s in the movie is going to be a great surprise and even if it’s not a surprise for people what he does is very, very entertaining and I think that people are going to enjoy seeing him have a little fun.

CS: How much did you and Robert prepare that back and forth last night onstage?

Stiller: We started working it up yesterday on the plane ride over. We knew that we had to say something. I’d never done one of these before where you just sort of introduce clips and I didn’t know what the expectation would be and so I just figured we should just do something short or whatever. I had one thought and Robert [Downey Jr.] had one idea and we were like, “Well, lets figure this out.” We got on the plane and then we started rehearsing it for like an hour before and then we said, “F**k it. It doesn’t even matter. It’s just a thing. Lets go have fun. Well, lets rehearse again.” So it literally became like we were working on the movie again because it was sort of in terms of the dynamic of the movie. It was fun and it took like an hour and a half, two hours. We were sort of obsessing in the car on the way over it.

CS: You got great laughs in the room. It was very, very funny.

Stiller: Yeah, good. Thanks. Those things, you don’t want to push it, but you also want to have fun and I think also knowing that they weren’t filming it or anything gave us a little freedom to say whatever.

CS: In the last few years, you’ve achieved the status of headlining big budget movies that have made a lot of money, but there’s always the argument about whether or not to do sequels to movies. Can you talk about your feelings about that?

Stiller: Well, I think it always depends on what the sequel is. I never did them until “Meet the Parents” and that was because Robert De Niro called me up and said, “You’re going to do the sequel. You’re going to do it, okay?” I was like, “Alright.” You really don’t want that call from De Niro and also that was just to work with those people in that cast, Barbra [Streisand] and the rest. It was like a once in a lifetime thing. On “Night at the Museum,” which you might be referring to, that was just that I thought they had a better script and they had a new idea and I really got a lot out of that movie. I just enjoyed doing it and the connection that kids have with it is just such a positive thing in my life. So I wanted to do it again and have fun doing it.

CS: Is it written by the same guys?

Stiller: Yeah. [Robert Ben] Garant and [Thomas] Lennon. It’s sort of a couple of other guys worked on it which is pretty much the same process that happened on the last one, in terms of all the writers who worked on it. It’s a couple of other guys, but they’re very much responsible for it because they created that world and they created the tone of that humor.

CS: So you’re at the Smithsonian for this one?

Stiller: The Smithsonian, yeah, and it’s like a whole other sort of group of new characters. It’s going to be a really cool cast which I don’t think I’m supposed to talk about it yet.

CS: Do you know how they’re going to bring the other characters over?

Stiller: Basically, they closed down the Museum of Natural History, the exhibits there, because they’re upgrading and so they put the old exhibits into storage and they send them to the Federal Archives in Washington. It’s some sort of magical logic for that movie that needs to happen.

CS: What is the running time on this movie and do you have anything lined up after “Night at the Museum 2”?

Stiller: I think the running time, it’s not locked yet, but it’s going to be somewhere like an hour forty-five. I don’t know. I have something that I might be doing, but I don’t yet, but I think that I’m going to take a little bit of time off.

CS: Has De Niro called you about “Meet the Little Focker” yet?

Stiller: Nobody; I’ve never heard anything about that except from journalists. If he does call though I’m in trouble.

CS: Is “Hardy Men” something on the horizon?

Stiller: It’s on the horizon, but not a reality yet.

Stiller’s Tropic Thunder opens everywhere on August 15.

*At a press conference before accepting the ShoWest Male Star of the Year, Downey Jr. talked about his character and explained exactly what he did that was so outrageous: “In ‘Tropic Thunder’ I play a guy named Kirk Lazarus, who I fashioned after Russell Crowe, Daniel Day-Lewis with a little Colin Farrell in there, those three guys or one guy are playing an African-American army sergeant in a very important Vietnam movie. The movie is such a complex plotline in itself than I think to talk about the mockumentary of your complex storyline might be more confusing than anyone can bear. In the mockumentary, as Kirk Lazarus is preparing, he went back and actually moved in with the man that the character he’s playing, who would be a 75-year-old African-American, he went in and moved in with his wife in Vietnam, so there are scenes where I’m with my Vietnamese family that’s not my family and I decided that I should start taking the psych meds of the character that I’m playing, this African-American Army sergeant, from when he was at the hospital so I could understand his experience more, and at one point in the documentary, I explain clearly how I built the pyramids.”