The British comic book “Judge Dredd” made its debut in the mid-1970s, a helmeted lawman who was judge, jury and executioner in a nearly lawless anarchy of the future. Coming out in the recession-wracked ’70s, when civil unrest were common in the U.K., U.S., and other corners of the West, one might see it as a celebration of a kind of Dirty Harry justice — simple, bloody solutions to socio-criminal ills.

Or maybe it was “a satirical response to Thatcherism,” says actor Karl Urban, who stars as the Judge in a new 3D movie, “Dredd 3D.” Margaret Thatcher wasn’t Prime Minister of Britain until 1979, but she was a well-known figure in mid-70s Britain, already the head of the Conservative Party there.

And what about Dredd today?

“Dredd is perfectly placed in our times,” says Urban, best-known for playing Dr. McCoy in the new big screen “Star Trek” franchise. “Our film is the perfect representation of the character that [author] John Wagner created back in ’75. In our movie, I see Dredd as a response to social unrest that’s errupted globally, and to society’s response to that unrest. Dredd is set in a world where the justice system has been given absolute power, the power to summarily execute a perp on the spot.

“Since the creation of Dredd, one can argue that there’s been a continual escalation of Big Brother, watching over all of us, a steady erosion of civil rights. Unfortunately, incidents like 9/11 have given us laws like The Patriot Act, a necessity for this day and age.

Thematically, Dredd was ahead of his time.”

The 40 year-old New Zealander endured months in a gym and weeks in a South African boot camp to get in shape to play the Judge.Afer all, Sylvester Stallone was the character’s previous big screen alter ego. The bigger challenge, Urban says, was acting behind a helmet and mask.

“It’s a challenge to communicate with the audience without the use of my eyes,” he says. “I had to use every other tool I have available to me. Obviously, the voice takes on heightened significance. As does the physicality, the wear the character carries himself. It was important to me to know what humanized Dredd. He’s just a man. He’s not a robot, not a super hero. He has no special powers. Just gadgets. It was important to me to know where his sense of humor lay, what angers him, what amuses him and what he does when he’s tired, or when he’s pumped up.”

The film is earning early praise from comic book fan websites and even the trade publication Variety noted that it “reinstates the somber brutality missing from the U.K. comicbook icon’s previous screen outing.” Urban hopes “we’ve made an instant cult classic. But let’s be honest, movies like this that open in September don’t do nearly the box office that summer films do. So while I would be delighted to play the character again, if it’s just a one-off experience, I’m still proud of it.”

Besides, Urban already has two franchises — maybe three — that he has obligations in. He returns as “Bones” McCoy in the next “Star Trek” film , “Star Trek into Darkness” in 2013. He’s a part of the Vin Diesel “Chronicles of Riddick” series. He may even reprise his secret agent role in the sequel to “RED,” the Bruce Willis/Helen Mirren action comedy. But it’s McCoy where his long-term plans lay, a character he lobbied hard for the chance to play, and a role he relishes.

“Think about it,” he says. “They’re action films, with heroes. And McCoy isn’t really heroic. He’s got this comic humanity that makes him stand out in that universe. Who wouldn’t love playing that?”