NEW YORK, NY.- Three years ago, Sean Ono Lennon was asked to develop a music video for the 50th anniversary of “Happy Xmas (War Is Over),” a 1971 protest song by his parents, John Lennon and Yoko Ono, which has become a rare type of perennial — a warmhearted Christmas tune that doubles as an anti-war challenge, telling ordinary citizens that peace can be achieved “if you want it.”

But Lennon, 48, was not interested in making a simple video. That “felt unnecessary” for such a well-known track, he said in a recent interview. What intrigued him more was the possibility of expanding the song’s message through a narrative film. After about two years of work, that project became “War Is Over! Inspired by the Music of John & Yoko,” directed by Dave Mullins, which has been nominated for an Academy Award for best animated short film.

The 11-minute picture is set in a World War I-like battle zone where two soldiers on opposing sides take part in a secret chess game, communicating their moves via a homing pigeon that dodges bombs over a snowy No Man’s Land. In the story’s climax, both armies are ordered into bloody hand-to-hand combat while the opening lines of John and Yoko’s song ring out: “So this is Christmas / And what have you done?”

For Sean Lennon, who in recent years has gradually taken on the responsibility of managing his parents’ artistic legacies — his mother, 91, has officially retired — the film is part of a continual process to keep that work relevant for younger generations. He is well aware that even a classic by a Beatle can fade away without tending.

“It’s not about mining the past,” Lennon said by phone. “You’re competing with generations of people who have not grown up with the same culture and art that most people my age and older take for granted. So, for me, it’s very important that the message of peace and love, which may be a trope, is not forgotten.

“What I don’t want,” he added, “is for my mother and father’s work to disappear with the sands of time.”

The film was made with the help of some substantial forces. Mullins was a longtime animator at Pixar, and in 2021, he joined Brad Booker, the film’s producer, in a new production company, ElectroLeague; “War Is Over” is its first completed project. The score is by Thomas Newman, the Oscar-nominated composer whose credits include “The Shawshank Redemption” and “Wall-E.” Lennon and Ono are among the executive producers.

Lennon was connected to Mullins through a mutual friend, and in an initial meeting, they came up with the basic concept of the war setting, the chess game and the messenger pigeon. Mullins said he wrote the full script immediately afterward. (Lennon and Mullins are credited with the film’s story, and Mullins has sole writing credit.)

Lennon had recently gotten to know director Peter Jackson through “The Beatles: Get Back,” his three-part, nearly eight-hour odyssey about the band’s troubled recording sessions in early 1969, and Lennon asked him for advice on “War Is Over.” Mullins recalled that at a dinner meeting with Lennon in March 2022, he watched in stunned silence as Lennon texted with Jackson, his phone emitting a little whistle as each message was sent.

“My heart was just beating a mile a minute,” Mullins recalled. “Like, oh, my God, Peter Jackson’s got our script!”

Jackson’s visual effects company, Weta FX, handled the animation for “War Is Over,” though Jackson himself was uninvolved. In an email, he said he only saw the film once it was completed.

“I’m genuinely proud to have played a tiny part in bringing it to life,” Jackson said. “It’s entertaining and charming — and celebrates humanity without preaching.”

The film was created with Unreal Engine, a platform that was originally developed for video games by the company behind Fortnite. The animation process involved performance capture: shooting real actors, whose movements become the raw material for computer animation later.

Extensive work went into crafting the look of the animation, which, despite being computer-generated, has a hand-drawn style, with outlines that can resemble charcoal sketches.

Production on “War Is Over” began before the Ukraine war broke out, and Hamas attacked Israel just as they were wrapping the project. But Lennon said the goal was always to make the story more universal.

“We tried to abstract the aesthetic of World War I into a sort of parallel dimension that wasn’t that war specifically,” he said.

In the film, the two armies wear insignia with opposing geometric designs: one side’s symbols are rounded, the other’s angular. The battle scenes show soldiers of multiple races and ethnicities, representing all humanity.

“Sean was adamant in our first conversation that he didn’t want the movie set in an identifiable war,” Jackson recalled. “He wanted the message from the song to be the focus, and not muddy it by having British fighting Germans, or Americans fighting Vietnamese.”

That message, and how it was delivered, was key to John Lennon and Yoko Ono’s work. Before “War Is Over” was a song, it was part of a series of peace protests that the couple enacted in various forms throughout 1969, including “bed-ins.” That December, they posted black-and-white billboards in 12 major cities around the world displaying variations of “War Is Over! If You Want It — Happy Christmas From John & Yoko.”

It was perhaps an early example of a guerrilla media campaign, using celebrity power to transmit a subversive message.

“I think you could argue,” Sean Lennon said, “that my mom and dad invented memes before that term even existed.”

“War Is Over” is the latest Beatle-related project that he has been involved with. He was a point of contact for Jackson on “Get Back” and on the release of “Now and Then,” the reworked 1970s John Lennon demo that was released in November as “the last Beatles song.”

For more than a decade, the Beatles, and each individual member, have been the subject of a series of reissues, repackagings and reexaminations of various kinds — and it is not over. Last month, it was announced that director Sam Mendes would make four biopics, one for each Beatle, which are expected in 2027.

Lennon, who remains an active musician — he released his latest album, “Asterisms,” last month — said he viewed “War Is Over” as the kind of project that allowed him to honor his parents’ legacies, an opportunity his mother provided.

“I’m just grateful that she’s given me the freedom to try to do weird things like this,” Lennon said. “You know, she’s still the queen of the family.”

This article originally appeared in The New York Times.