The moment the first trailer for Civil War dropped, people immediately began asking if it was such a great idea to release a film about the collapse of American democracy in an election year. With increasing political polarisation, and 43 per cent of Americans believing a real-life civil war is a distinct possibility, could this be the spark that sets it off?

Perhaps surprisingly, Alex Garland, writer-director of the movie that stars Kirsten Dunst, doesn’t dismiss that concern out of hand.

“The incitement question is interesting,” he says. “It’s just that to know the answer to it, you would have to be in possession of a lot of other information, and you’d have to be able to project into the future and anticipate behaviour. There’s a lot of unknowns there.

“But if you look at the counter-position, which is silencing, there are fewer unknowns. There are significant dangers involved in either silencing other people or silencing yourself, which are quite predictable and quite well-documented. So I can’t prove it with the positive, but in a way I can prove it with the negative.”

That might sound like he’s making the case for the right to free speech, regardless of its impacts, and that might seem to put him on the side of the right. But that’s not where he, or his film, actually sits.

Civil War follows a small band of journalists, including Dunst, Wagner Moura and Cailee Spaeny, as they travel across the eastern seaboard of the US hoping to cover the front line of the conflict, and to score an interview with the president (Nick Offerman). It’s a road movie through an America ripped apart by divisions the ballot box can no longer contain, where militias are engaged in open combat, the streets are no longer safe, and atrocities are commonplace.

If there are sides here, it’s difficult to know which one we should be barracking for. But not impossible, insists Garland.

“There is a side it comes down against, and there’s a side it comes down for, by implication,” he says. “The side it comes down against is fascists.

“It’s just not taking sides in the terms some people might want it to take, which would be, ‘I’m left-wing, I wanted to attack the right’ or ‘I’m right-wing, I wanted to attack the left’. It’s deliberately taking that out. It’s an old-fashioned way of thinking – a centrist way of thinking, actually – that says governments are there, systems of checks and balances are there, to guard against fascism. That’s why they exist.”

Civil War is a very modern edge-of-the-seat immersion in the hell, and the fog, of war. But it is old-fashioned in another way: the journalists (Kirsten Dunst and Cailee Spaeny are the photographers, Wagner Moura and Stephen McKinley Henderson the writers) are its heroes.

The film brilliantly captures the adrenaline addiction, and the trauma, that can grip conflict journalists. But that in no way negates the absolutely critical role they play in keeping us informed – and safe from tyranny.

Garland grew up around journalists. His father was a political cartoonist for The Daily Telegraph, Spectator and New Statesman (and the co-creator, with Barry Humphries, of the Barry McKenzie comic strip in Private Eye in the 1960s).

Today, he concedes, “journalism is a much-maligned profession. And I find that surreal. It’s like maligning doctors. You just try living in a society where journalists have been erased, where they are no longer holding people to account, and see where it gets you. And you could say we are starting to see what that is like anyway.”

Sometimes, he says, he likes to play a little thought experiment in which he imagines a modern-day Watergate, complete with Woodward and Bernstein exposing deep corruption at the highest levels. “Would it lead to the downfall of that government? At the moment, not necessarily.”

Garland burst onto the scene as the 26-year-old author of runaway bestseller The Beach back in 1996 and has since enjoyed considerable success as a screenwriter (28 Days Later, Never Let Me Go) and writer-director (Ex-Machina, Annihilation, Men, the TV series Devs). If there’s a strand that unites this body of work, he says, it is an obsession with fascistic power structures and personalities.

Journalism is a much-maligned profession. And I find that surreal. It’s like maligning doctors.

Alex Garland

“Even The Beach is sort of about that, really, the different spaces fascist thinking can come from. I think that’s probably because I was born in 1970, and the Second World War, and the things surrounding it, simply did not feel distant.”

These days, he says, fascism seems to be a more abstract concept to people, particularly in the Western democracies. And that is a danger.

“When they see it at all, they see it as something either historically or geographically distant. And that allows for fascism creeping into their own behaviour, even though they would not ever consider themselves to be fascists. It’s an evolutionary process that can be quieter and more insidious than people realise.”

Do you mean to suggest that there’s an innate drift towards fascism, and that without the safeguards of strong public institutions, courts, and media, we risk an inexorable slide into it?

“Yes,” he says. “It is avoided by rational, compassionate thinking, and it’s avoided by systems. It is not arbitrary that we have those systems; those systems were created thoughtfully, primarily as a protection against extremism.”

In truth, Civil War isn’t intended as an incitement, but as a warning.

“The problem presented in the film is that a populist politics, a divided country, journalists and the fourth estate not having the power and the traction they need to hold people to account, has led to an authoritarian in power,” he says. “If you erode the media in a certain kind of way, or you break apart some of the systems of government, the thing you are guarding against might actually occur. We act as if we’re not guarding against something real, but I think we are.”

But it’s not just the US we should be concerned about, he says, pointing to the impunity with which Boris Johnson lied his way through his prime ministership in Britain. It’s all the other places, too, where so-called “strong” leaders have emerged and sought to weaken the institutions that protect civil society. And it’s also the impact a weakened, and morally diminished, America has on the rest of the world.

“What does that allow other countries to do – maybe other countries that are expansionist and violent and authoritarian? What has been permitted by that chaos? It’s an interrelated problem, which is explicitly not localised to America, either in its cause or in its effect.”

It’s a grim prognosis. Do you think there’s any way back?

“Absolutely, of course,” he says. “If you can come back from World War Two and that scale of expansionist, psychopathic behaviour and genocide, then yeah, of course there’s a way back. But it’s a way back that has to be taken.

“Humans are often very good at correctly anticipating a problem, but much less good at acting on it. They see the tsunami coming, and they all stand around pointing at it, but do they actually do anything, build defences, run away, whatever it happens to be?

“I get the sense that the great big wave is on its way, and the water is sucking out down the shore at a rather alarming rate,” he says. “That’s where we are right now. There might be a tsunami, and so we should react to that.”

Civil War is in cinemas now.

Contact the author at kquinn@theage.com.au, follow him on Facebook at karlquinnjournalist and on Twitter @karlkwin, and read more of his work here.