Something has gone terribly wrong in the United States of America. Texas and California have seceded from the union, leading to an all-out war between those secessionists and the Washington government. Photojournalist Lee Smith (Kirsten Dunst), accompanied by both veteran and trainee colleagues (Wagner Moura, Cailee Spaeny, Stephen McKinley Henderson), travels through the American war zone from New York to DC in the hope of scoring an exclusive interview with the President.

Alex Garland’s Civil War is a slippery thing of a movie, straddling a weird nexus between what prospective audiences think it will be about, what the film claims it is about, and what it actually appears to be about. It is certainly a contentious move, given the democratic crisis which the USA currently finds itself, to posit a near future America where the political differences have become so polarised as to fracture the country for the first time since 1865. One can be forgiven for mistaking Civil War to be a left-wing polemic on the risk of Donald Trump reassuming the Presidency and the ‘make American great again’ Republicans destroying what remains of American democracy.

In the viewing however, Civil War focuses very closely on the process of war. By following a small group of journalists through an episodic series of encounters – warzones, street battles, refugee camps, and some horrifying atrocities – it showcases the very human cost of war. It particularly showcases the sort of repellent urban warfare in which body counts are high and the civilian cost can be catastrophic. In the context of Russia’s attempted invasion of Ukraine, and Israel’s devastating attacks in Gaza, Civil War feels particularly timely. It is very effectively shot, with remarkable cinematography from regular Garland colleague Rob Hardy.

More than anything else Civil War is a film about war journalism. As Smith, Dunst gives an outstanding performance that ripples with inner conflict: cynicism versus idealism, resolve versus vulnerability. Dunst has always been a strong actor, but her work here seems particularly powerful and naturalistic. It is a shame that the film’s genre will likely preclude her from getting the acclaim she deserves. It is also great to see the much underrated Stephen McKinley Henderson tackle a role worthy of his talents. As the hopeful young Jessie, Cailee Spaeny provides a hugely engaging viewpoint for the audience.

The film makes it viscerally clear that being a journalist in a war zone is a horrible position in which to be. In constant and palpable danger of getting killed, the journalist is faced with atrocity yet is forced to view and record them without acting to prevent their occurrence. Many of the films stronger moments reflect the stress and inhumanity – and their impact on the people bringing the news from the front. One could criticise the nuts and bolts of Garland’s script, which to be fair is a reasonably predictable affair, but it nails the emotion and serves its thematic purpose.

Pains have been taken by Garland’s screenplay to depoliticise the precise nature of the second civil war. The war’s origins are deliberately withheld, and details are regularly obfuscated. In addition, the split of Republican-dominated Texas and Democrat-dominated California from the rest of the country goes some way to avoid the story being seen as a right-versus-left conflict.

Then someone – a soldier played in a striking cameo by Jesse Plemons – asks the question: ‘are you an American?’ It’s a moment that throws Garland’s entire effort to be apolitical into redundancy. It is a hugely tense, masterfully constructed scene. To a large extent it makes the movie the creative success that it is. It also makes it potently clear that of course the film is about Donald Trump. How could it not be about MAGA Republicans, and their fears of immigration, and foreigners, and a loss of dictatorial control? Civil War is not a polemic, but it is a mirror to the USA’s political crisis. It also resembles a warning: this is how bad things could become unless the country pulls back, and calms down.