The stages of his fame are clear enough: In 2002, Dirty Pretty Things makes Chiwetel Ejiofor an art house star. 2006, the Inside Man plants him firmly in the region of Hollywood stardom—he plays Denzel Washington's sidekick. And 2008, David Mamet's Redbelt positions him as the star of a Hollywood movie. I asked the British-born Nigerian actor about his role in Redbelt—a martial arts instructor who struggles to maintain his moral values in a corrupt world—and his director.

How did you and Mamet get together for this project?

Well, we share an agent, David and I. And so he was able to introduce David to a lot of my work. And the next thing that happened effectively was that David sent me the script so I could be a part of this film. And you know, I was very excited because I love David Mamet's work, and I've been aware of his work ever since I started acting in my early teens. So I was thrilled to get a chance to read it and get a chance to speak to him about it.

The moral direction of the character you play, Mike Terry, is guided by ancient codes of fighting and living.

Yes, it's that old-world kind of feel. This film is a sort of samurai flick about people that have these codes and try to implement them. And I think one of the things that's interesting is that you have these old codes of conduct in the Brazilian jujitsu world. The old in the new. The ancient in the modern.

Mike Terry recalls Aristotle's theory of an action. An act can begin with a good intention but end with bad consequences.

You know, people do live a certain way. I think that's what fascinated David. How does that way of living then exist in a contemporary, confusing, morally ambiguous context of modern-day society? And does it have a place? Is it combustible? Does it fit in all right? Does it skirt around the edges? Does it allow people to find you vulnerable? Do people find you naïve? Do they find you easy to manipulate? And I think these are the questions that first intrigued David about this film, about this project.

And you?

It certainly intrigued me as an actor about playing this part, and seeing, and answering those kinds of questions. And seeing if there is a way for this character to hold his moral opinion yet still negotiate the shark-infested waters, if you like, of the fighting industry. And obviously the film concludes that it's quite complicated. And that this character finds it complicated, and has to reach into other areas of himself in order to redefine what he means by having a code of honor, when forced into conflict with other forces. And I don't think it's a kind of simple morality tale. I think it's a question of—it's all very well and good having honor, having morality, but if you're going to really get out there and invest in contemporary society, you have to be prepared to define what that means and what it means to other people and what it means to yourself, and what you're prepared to fight for in the end.