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 says 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?”