Norton plays the inscrutable Eric Byer, the mastermind behind a blackline agency looking to track down Jeremy Renner's rogue operative from the Outcome programme. The film opens up the Bourne universe, with events running parallel to The Bourne Ultimatum.
Digital Spy sat down with Norton to discuss the difference between Bourne and Bond, playing an antagonist with shades of grey and how DVD saved his '90s classic Fight Club.
What do you think the Bourne movies have that separates them from the rest of the blockbuster crowd?
"I think they've always pulled a little more from the authentic reality of what we glimpse in the headlines. I think that on the other end of the spectrum you've got sort of like the Mission: Impossible or James Bond, which I would call more in the fantasy superhero genre. Those are more spectacle and, in the Bond case, slightly tongue in cheek, even in their newer grittier form.
"In the Bourne films, nobody was ever going to climb a building in gecko gloves, or parachute in a car out of a plane. They were always much more lo-fi - I think trafficking in sort of a more realistic sense of how does the government actually function. I think Tony's gone even one step further in this one, in the sense that he's opened it up to start to include government-based science.
"He's really starting to kind of exfoliate the way that the matrix of government, science, corporations and military comes together. I think that there's a lot about it that feels pulled from the things we're hearing about each month. We know there's a lot of drone strikes going on in the world, so Tony kind of peeks behind the curtain and shows us what that's like inside. It's fun, there's a little bit more authenticity."
Tony has spoken about doing research into DARPA (Defence Advanced Research Projects Agency) and basing Bourne Legacy's organisation NRAG (National Research Assay Group) on it - did he share much of his findings with you?
"Oh yeah. He gave me a cinder block of paperwork. At one point he had this folder, and I was like, 'You've gotta be kidding me, we're living in a paperless world.' and he was like, 'Alright, alright, I'll send it to you in an email.' He sent me this email that was like my bouquet, and I opened it up and it had 39 attachments, and links and references. I've never had anybody deliver me my work full stop like that. Here's everything, read, absorb, see you on the first day."
How important was it for you to make sure Byer wasn't a moustache-twirling villain?
"I think when you talk about someone as a villain I think of someone like Moriarty, they delight in what they're doing. I just don't think that's the world Tony writes. I think Tony looks at my character as a guy who's a patriot, who really believes in what he's doing, who by the way, from the get-go is incredibly frustrated with the corner he's being painted into. To him it's the burden of the job, it's the burden of what comes with his very difficult job, not at all his plan. It's kind of a horrible, necessary decision within a really bad situation."
Did you think much about Byer's personal history? Is that helpful for your performance or is the script itself the key?
"Tony and I would talk about some of those things just to try and get a bead in him a little bit. But I do think Tony very purposely sort of cloistered these people. The most that you're seeing outside the sphere of their work is when you see that he has a very direct relationship with this guy, that he knew him, coached him, mentored him. It adds some weight to his decision."
How does Jeremy's character differ from Jason Bourne?
"Tony said once that the difference in Jeremy's character and Matt's from the first trilogy, is that Matt's is fundamentally trying to find out who he is, and is afraid that the more he finds out the worse it sounds. In other words, he's beginning to realise that he's been something very bad.
"But Tony's point was that Jeremy's character signed up, signed in, he bought in and what starts coming down on him is the rules of the game, he's not lily-white, he's been a willing participant in a system in which he's expendable."
Are you hoping to come back for more Bourne movies?
"I don't presume to say what I would like, but I think the reason to do even this one, was that I really like Tony's films. I like the project. I think he's been engaged in sort of trying to poke a fork in this idea of an institutionalised corporation that is anti-democratic, where things are being done that don't represent who we want to be.
"I think in a lot of Tony's films, if you look at them, there's this threat of totalitarianism through corporations through government. I think it's very topical, it's very much the theme of the time we're living in. It's what Occupy is all about, and I think in his own way that Tony is prodding at that. I just thought it was fun to be a part of, and I can't say how far he'll want to go with it. If he wants to keep going I'm down for it."
Some of those ideas overlap with Fight Club - are these things that interest you?
"Yeah, I think that people relate to them. I think it's a theme of the times. People are worried about the degree to which corporate interest is starting to threaten human interest. I would say if you had to ask people in the progressive side of US society to say what do they think is the single biggest threat, they'd say this court decision that defined a corporation as having the same rights as a person. It's right at the forefront of people's concerns right now."
In terms of your career outlook now, are you interested in doing more films like this or doing smaller-scale stories?
"I'm drawn to people and ideas more than I am towards the scale of it. I had a huge amount of fun doing a $15 million (£9.7 million) film with Wes Anderson (Moonrise Kingdom) right before doing this one - this was ten times the budget with Tony. It's much more to be about feeling nicely in line with the people I'm involved with. At this point in my life I'm not bent on proving anything, really. I just like working with smart people."
I did enjoy your very brief scene in Sacha Baron Cohen's The Dictator...
"Ha, yeah! But Sacha is one of those people. I think Sacha is a genius and we're friends and it's fun to do something with him."
Does this mean we're going to see you show up in a comedy like The Hangover 3?
"I hope they don't make that movie, but maybe they will."
Have you heard anything more about the Fight Club musical that David Fincher and Trent Reznor have been touting?
"I will be in the second row for the premiere. I'm sure neither Brad Pitt nor I will get invited to sing in it, but that would really make me laugh."
Do you think a movie like Fight Club would get made today?
"I think it would be much harder today. It's right in that middle budget range that no one wants to touch anymore. And DVDs are disappearing, no-one's going to buy a DVD in three years. It was kind of the secondary revenue that prompted them to make films like that. The digital, on-demand and the subscription services, Netflix or Amazon, the revenues coming back from that are kind of pennies on the dollar to what it was to sell a DVD, so it's much harder."
You directed yourself a while back - are there any plans for you to return to that?
"It depends on the project, but yeah I've got my eye on doing that again."
Will you be back for Wes Anderson Budapest Hotel with Johnny Depp?
"Wes knows I'm in his troupe, I'm in Wes's repertory company any time he wants, and we've talked about it, and I think he's assembling it soon."
The Bourne Legacy opens in cinemas on August 13.