‘Warfare shows the futility of war even as it celebrates the bravery of soldiers’

This week sees the release of Warfare, a pulse-pounding new film from Alex Garland, this time working with Ray Mendoza as co-director, an Iraq War veteran turned filmmaker. As you'd expect from the filmmaker behind Dredd and Civil War, it's dramatically compelling and utterly propulsive.

But what's interesting this time is Mendoza’s contribution, creating a sense of veracity and visceral experience that both adds to the film and, perhaps, limits it.

The situation is based on a real 2006 operation that Mendoza participated in during the war in Iraq. A team of US Navy SEALs occupy a house in Ramadi for an operation, but find themselves surrounded and under threat. As they await evacuation, it becomes a race against time to protect their injured and get home alive.

Even in an era that prizes truism in our war films, where actors regularly head off to boot camp to learn the muscle memory and discipline necessary to convince as a cohesive, interdependent unit, this film stands out.

Mendoza started with his own memories of a real mission, and then reached out to the men of his unit to gather their recollections and attempt to build a true and rounded portrait of what happened with Garland's help. Then they put that onscreen without dazzle, in more-or-less real time, so that the moments of boredom stand right alongside the petrifying action. This is not meant as a pro- or anti-war movie according to its makers; just a depiction of war as it is fought.

There's no music, just an inventive sound mix that focuses — as anyone would — on the sounds of nearby bullets, of friends screaming in pain, of the horrible looming silence when you know enemies are near. The cast throw around military jargon but barely name one another; there are no pauses to talk about their sweethearts back home or to reminisce about mum's apple pie.

That's down to Mendoza and Garland's determination to focus on realism, the experience of men on the ground. One minute you're cheering along to a sexy music video; next minute, maybe, you're victim to an IED and struggling for your life.

It's powerful, in the way that any true portrait is powerful. There's a satisfaction in seeing a difficult thing done well, whether that’s expertly robbing a casino or dancing the tango or, yes, taking control of a building.

Both the actors and the men they portray worked extremely hard to become a cohesive and effective unit, and the sense of camaraderie and brotherhood between them is heartwarming. And then, suddenly, it becomes gut-wrenching, when one of their number is hurt, and the audience is catapulted into the horror of war.

Those injuries, incidentally, are portrayed in all their bloody reality as well, as are the bodies of those killed; this is not for the weak of stomach. But war films should not be a comforting, easy watch. We're long past the heroic derring-do of early John Wayne, or the stiff upper lip clichés of World War II-era British propaganda, and it's important to know that war is messy and brutal and nothing like a video game.

Yet the close focus on those personal relationships and the moment-to-moment conduct of war is also, ultimately, only part of the picture. There's very little sense in this film of what the mission is, who the enemy is, and what has actually been accomplished by all this sound and fury.

Mendoza, in interviews, has talked about how little many of the men in the unit remembered about the two Iraqi families who lived in the building they occupied; some didn’t remember them being present at all. “We weren't there for them,” he said.

It's also striking that, in a film that once again emphasises how US troops hate to leave a downed man behind - here they also risk their lives to retrieve mere equipment — no one collects the body of one of their Iraqi allies. It’s left lying in the street where he fell, defending them.

The most striking feature of this modern war film is therefore how little it says. Some brave, hard-working young men are put in harm’s way for no obvious reason and do their best to get one another home. That's personally laudable, but was their sacrifice worthwhile to any degree? Is there any way in which this is a “good” war, like World War II, or a “bad” war, like Vietnam? The filmmakers don't touch that, and that is something of a trend.

Black Hawk Down was criticised when it came out for saying so little about what the Americans were actually doing in Somalia, and whether any of it had value. Now that same approach seems to be the norm: portray the soldiers’ personal heroism, but never examine the bigger picture.

Yet surely the bigger picture is more important to interrogate than ever? It may seem didactic or scolding or boringly obvious to say that war is bad, and apparently some veterans worry that it is the same thing as saying soldiers are bad (it is not). Still, it is worth saying, as politicians turn to jingoism to ramp up their faltering support. War is bad, and Iraq was particularly bad, and the fact that good men tried their best to keep one another alive doesn't change that.

All of the bravery and struggle and sacrifice portrayed here is futile if it does not contribute to some greater cause — and one is left with the sinking feeling that it did not. So Warfare is worth seeing, if you can stomach it, but it's only a tiny part of the whole picture.

Warfare premieres in UK cinemas on Friday, 18 April.