Just because the civil war ended more than 150 years ago doesn’t mean the US has stopped fighting it. The Confederate flag still prompts passionate protest but today’s preferred theatre of combat is the movie one. And judging by recent civil war movies, there is no amnesty in sight.

Sofia Coppola’s The Beguiled opens up a new front. Based on a 1966 novel (as was Don Siegel’s 1971 film), it puts a Yankee deserter (Colin Farrell) into Nicole Kidman’s Virginia school for repressed maidens. Coppola tracks the rooster-in-the-henhouse dynamic with her usual sun-dappled semi-abstraction. However, her movie has raised awkward questions, such as: “Where are all the black people?”

Coppola’s version excises some of the book’s more exploitative elements and puts the emphasis on the women, but she also casts Kirsten Dunst as what was previously a mixed-race character, and cuts out the story’s sole African American character: a slave woman. Coppola’s defence is: “Young girls watch my films and this was not the depiction of an African American character I would want to show them.” So she shows them no African Americans at all, which is hardly an advance on Gone With the Wind.

Watch the trailer for The Beguiled.

Do race and gender have to be a zero-sum game? Looking at recent takes on the civil war, apparently so. Nate Parker’s The Birth of a Nation, dramatising a real-life 1831 slave rebellion that catalysed the war, was a corrective to DW Griffiths’s infamous 1915 Klan-cheerleading atrocity of the same name, but past rape allegations against Parker tarnished the film indelibly. Last year’s Free State of Jones had its (bleeding) heart in the right place, with Matthew McConaughey leading a multiracial militia against the Confederacy and establishing a civil rights-respecting oasis. But the story couldn’t avoid falling into the old “white male saviour” trap. Glory (1989) was a magnificent civil war movie with barely a woman in it; Cold Mountain (2003) an OK civil war movie with barely a black person in it; while Ang Lee’s Ride With the Devil (1999) felt longer than the war itself.

The only recent film to have even vaguely squared this circle was 2015’s The Keeping Room, a modest little western in which the civil war played out in a similar microcosm to that of The Beguiled (a house of women besieged by marauding men). Except that in The Keeping Room, one of the women is a black former slave. And they have shotguns. It wasn’t perfect, but when it comes to civil war movies, very little is.

The Beguiled is in cinemas from 14 July