THE road that an idea takes from the screenwriter’s mind to your local multiplex is besieged by obstacles political, financial and practical in nature. The average blockbuster has to contend with budget fights and studio meddling; a film like “The Promise” is even trickier to bring to the screen. A sweeping historical drama about a national tragedy, it is the sort of movie that Hollywood used to love. But for more than a century, writers and studios have turned their faces away from the story. In many ways, the film succeeds simply by exploring an event that others will not.

Taking place in 1915, “The Promise” centres on a passionate love triangle but is set against the genocide perpetrated against Armenians by officials of the Ottoman Empire. Oscar Isaac plays a humble Armenian medical student who tries to escape the massacre and save his family, while falling in love with an American dance instructor (Charlotte Le Bon) thereby earning a rivalry with her journalist boyfriend (Christian Bale). It is a stirring, if somewhat by-the-numbers depiction of heroism and survival in horrifying times, but it will not make the pantheon of great historical films. The love story is shallowly written, and the charismatic performers often wilt under the haunting scenes of systemic violence. Without a meaningful story on which to hang its historical events, the actors are left looking like vehicles for a history lesson.

Perhaps that is what the film-makers intended. “I didn’t know about the Armenian genocide before,” Mr Isaac noted. “I think, unfortunately, a lot of us in this country and in the West and all around the world have been purposefully kept in the dark about it.” Indeed, the most basic facts are in dispute. Turkey claims that 500,000 Armenians died of hunger and disease in the Syrian desert: they were being deported for supporting Russia in the first world war. Armenian survivors and their descendants place the number of dead at 1.5m, observing Armenian Genocide Remembrance Day on April 24th every year. They argue that it was a systematic killing rather than an unfortunate side effect of poorly executed policy.

Today most scholars recognise the massacre as genocide, yet many Turkish officials still do not. Because Turkey is such an important ally to the West, neither has America, Britain or Israel. On the campaign trail in 2008, Barack Obama pledged several times to reverse this policy of obfuscation, but he failed to do so once in office. This week, Donald Trump declined to categorise the events depicted in “The Promise” as genocide (though he was happy to call it “one of the worst mass atrocities of the 20th century”). America’s cultural machine is doing what its political machine will not.

“The Promise” is not for the squeamish. The slaughter is depicted with stark brutality and inarguable cruelty. Key characters are executed suddenly and without warning. A mother is shot in the head in front of her daughter. The population of an entire town is butchered in the matter of minutes, their bodies piled on top of each other beside a river. The film-makers do not use the word “genocide” until the film’s closing moments, but they do not need to: the actions are unmistakable. In one key scene, Mr Isaac’s character discovers a train full of starving Armenians, a sequence often found in Holocaust films, placing these dreadful events in moral context for the audience.

Indeed, while other genocides have found their way to the screen, politics seems to have prevented “The Promise” from making it through the typical channels. Studios are unlikely to take a chance on an expensive film that might anger government officials and geopolitical allies unless they can guarantee that it will be profitable. The film was instead independently financed by the late Kirk Kerkorian, an American billionaire of Armenian descent, who created a film company—Survival Pictures—with the express purpose of educating the world about the Armenian genocide. He sunk $100m into “The Promise”, casting Mr Bale and Mr Isaac to attract an audience. The choice of Terry George as director was inspired, too: his “Hotel Rwanda” (2004) proved that he is able to handle complex conflicts with nuance and sensitivity.

Still, when the film premiered at the Toronto International Film Festival in 2016, it did not set the festival alight. Reviews were middling, and no major distributors were interested. Open Road, a smaller company that had shepherded “Spotlight” to a best picture Oscar, picked it up, decided it wasn’t good enough for awards season, and dumped it in the spring. In its opening weekend it grossed only $4.1m, a historically low amount for a film that cost $100m to make. Insiders speculate that it could gross around $20m worldwide, which by most accounts would make “The Promise” a spectacular failure.

But “The Promise” cannot be judged in purely economic terms, as Kekorian had little interest in making back his investment. Perhaps we should not judge it on purely artistic terms either. “The Promise” doesn’t seek to break ground: it was created in order to shine light on an oft-ignored historical event, and even with mediocre reviews and middling box-office figures it is achieving that aim. One day, if the history of the Armenian genocide is officially re-written, “The Promise” will have played a part.