Screenwriter Reed Van Dyk was leafing through a magazine one day in 2012 when he came across an article about the human cost of war that stopped him in his tracks.
He knew that one day he would have to bring it to the screen, but he did not feel he had the leverage in Hollywood to tackle such a weighty issue.
"I wasn't in a position to make a film about this back then," he told AFP.
That all changed after his short film "DeKalb Elementary" won critical acclaim and earned an Oscar nomination in 2018, so he went back to the New Yorker article and began work on "Atonement," which goes on limited release on Friday.
The film, based on the magazine piece, begins in 2003, when the lives of an Iraqi family and a war veteran became tragically intertwined in a Baghdad under fire.
Mariam Khachaturian, played by Hiam Abbass, and her family are trying to reach their home when their two vehicles are fired on by a Marine unit that believed it was under threat.
Three passengers die in the shooting, including Mariam's husband.
Eventually, the widow tries to leave the war behind by moving to the United States with her daughter.
Marine Lou D'Alessandro (Boyd Holbrook) also wants to move on, but the consequences of what he was involved in continue to haunt him.
The only way he feels he might be able to exorcise his demons is to seek out Mariam.
"I was so touched by this piece of writing and the story and all these characters and the way that their lives had intersected very tragically, and then by some miracle, they all intersect again a decade later," Van Dyk said.
In the movie, Lou and Mariam sit face-to-face in California, brought together by the efforts of Michael Reid (Kenneth Branagh), a journalist who had interviewed both of them about the war.
"I was very drawn to the idea of that complexity, and very drawn to the idea of being this witness at this remarkable meeting over years with two people trying to process the enormous pain and loss of very different kinds," Branagh told AFP on the sidelines of the Toronto International Film Festival.
"And then the really compelling drama of this immensely difficult thing, meeting again to feel, discuss, forget, forgive," said the British actor, whose character is inspired by journalist Dexter Filkins, author of the original article.
- 'A new context' -
"Atonement" arrives in US theaters days after the US formally ended its decades-long mission in Iraq, but with the country again at war -- this time with Iran.
"I was pulled to write about and explore these trio of people, and so that was in spite of the fact that you know it wasn't a story that headlines were echoing at the time of my writing," Van Dyk said.
But "as we're making the film, the world has sort of backslid into war everywhere. So it brings a new context to all of our work."
For Holbrook ("Narcos"), portraying the tormented Lou was "a fantastic experience," but also an intimidating one.
"The preparation for a film like this is everything, and for me it was life altering," he told AFP.
"It was something that I had to really find and discover in myself, the empathy and the courage that [his character] Lou had."
Abbass ("Blade Runner 2049" and "Succession") said she had wanted desperately to do justice to Mariam.
"I wanted to take her place and shout out my feelings and my anger towards why this should happen," she said.
"Why on Earth we keep going all the time, causing these pains to people, whoever they are, whatever they are, whatever nationality they come from, whatever conflict we're talking about."
