Nolan on How Oppenheimer’s A-List Cast is a Throwback to 'Event' Movies Like Superman '78 and JFK

We've said it before and we'll say it again: 2023 is the year of the ensemble.

The summer's biggest blockbuster releases — Fast X, Spider-Man: Across the Spider-Verse, Asteroid City, Mission: Impossible - Dead Reckoning Part One, Oppenheimer, and Barbie — feature some of the most impressive casts assembled in recent memory.

While the impressive lineup for Oppenheimer certainly represents the biggest collection of actors Christopher Nolan has ever worked with, it's simply a reflection of what the filmmaker has tried to do since making the jump to big-budget studio projects nearly two decades ago. "When I was casting Batman Begins, my pitch to the studio was, 'I want to do what Dick Donner did in the 1978 Superman," the writer/director/producer recalled during an interview with Total Film (the magazine's latest issue is now on sale).

RELATED: Matt Damon On Barbie vs. Oppenheimer: "People Are Allowed to Go See 2 Movies in a Weekend"

He continued: "I remember as a kid just seeing these big actors — Glen Ford... Marlon Brando... Gene Hackman... this incredible cast. It made the film feel so big... That was something that went out of pop filmmaking in some ways. With Batman Begins, we really tried to bring it back. So whilst I've always tried to cast the best possible actors, there's a reason that a lot of movie starts are where they are. It's for me, a really fun and challenging combination of an incredible ensemble, but the film is so focused on one man's experience, and one man's view of the world."

OPPENHEIMER Photo: Universal Studios

That "one man" is J. Robert Oppenheimer (portrayed by longtime Nolan collaborator, Cillian Murphy), leading scientist behind the highly-classified World War II program that led to the creation of the world's first atomic weapons. Oppenheimer ultimately fell out of love with the bomb — pulling a reverse Doctor Strangelove, if you will — and found himself blacklisted for his "un-American" viewpoints.

Clocking in at three hours long, the film covers a megaton of historical background. With so much ground to cover, the explosive project required a parade of equally explosive A-listers to match its unparalleled scope:

Matt Damon (Leslie Groves), Emily Blunt (Katherine "Kitty" Oppenheimer), Robert Downey Jr. (Lewis Strauss), Florence Pugh (Jean Tatlock), Josh Hartnett (Ernest Lawrence), Michael Angarano (Robert Serber), Kenneth Branagh, Rami Malek, Josh Peck, Alden Ehrenreich, David Dastmalchian, Dane DeHaan, Jack Quaid, Matthew Modine, Dylan Arnold, and David Krumholtz.

"The awareness comes in when you start talking to the studio about: 'What are the precedents?'" Nolan explained, citing Oliver Stone's JFK as another exemplar. "[It] was an event: a big movie and a big, big experience for people."

Also speaking with TF, Hartnett said he expected the production's sheer concentration of celebrities to kick off a chain reaction of clashing egos. Thankfully, "you don't see that on Christopher Nolan's films," he added.

"I think because everybody knows that they're there for a very specific reason, and they're there to support the film and the filmmaker. So the egos art sort of checked at the door, and therefore you're allowed to be much more sort of natural, and to be yourself, on set and off. And when you're shooting in the middle of nowhere, you get to know people fairly well."

Oppenheimer will detonate a bomb of enriched acting talent when the film opens on the big screen Friday, July 21.

Jonesing for another thriller based on true events? A Friend of the Family is now streaming on Peacock.