Dunkirk is an incredible film, but probably not the one you’re expecting. It is, obviously, a war film, only it isn’t. All the conventions and rhythms of what we understand as war cinema – from Bridge Over The River Kwai to Saving Private Ryan – are largely eschewed, with Christopher Nolan favouring the kinetic pacing and claustrophobic camera work of a situational thriller. Yes, there are still trite touchstones that mar the experience – tonally dissonant cheering crowds and Kenneth Branagh’s overwritten role as Admiral Exposition – but these are negligible scratches on a juggernaut. Nolan’s film is insufferably tense in the best possible way, deeply moving (having earned its eventual sentimentality), and stunningly rendered.

What’s interesting, is that it’s probably Nolan’s least Nolan film – narratively straightforward with naturalistic performances and dialogue – which should win over cynics disaffected by Interstellar and Inception’s (over?)ambition. It’s even more elementary than most war films, hardly cinema’s most elaborate genre. There’s no contrived subplots, no lazy sympathy-wringing about kids or fiancées back home with wistful flashbacks, just an undiluted gazing into bedlam. In an interview with Sight & Sound magazine Nolan referenced Henri-George Clouzot’s suspense thriller The Wages of Fear as more of an inspiration than any war film, and such influence is palpable. The camera can be sprawling and clean in its anxiety, chronicling the vast empty expansion of Dunkirk’s overcast shoreline in murky greys and barely-blue-blues, before dismantling pacts of personal space with oppressive and cluttered gawps into decaying and drowning faces both metaphorical and very literal, recalling both Clouzot and that other master of the disorienting close-up, Sergio Leone. Shout-out to the near-peerless DP Hoyte Van Hoytema here; whereas his wide-eyed gaze invoked wonder in Interstellar, here it’s multifarious, beautiful and hideous often at the same time.

Despite its formal realism, it wouldn’t be a Christopher Nolan film without temporal splicing. It evolves over three segments; the first follows a nameless Tommy (Fionn Whitehead) takes place over one week; the second, Mr. Dawson’s (Mark Rylance) rescue attempt as part of the civilian fleet over one day; the last, squeezes inside Farrier’s (Tom Hardy) Spitfire over one hour. These timelines liaise and overlap with one another, but remain effectually coherent (serious credit to the editing team here); and their persevering interlacing builds tension better than the sharpest camera work or shrillest soundtrack; which Dunkirk also ably provides.

I’m one of those jarring curiosities that’s both a Nolan apologist (I adore both models of blockbuster polarisation Interstellar and Inception) and a Zimmer sceptic (farting French Horns have never really done anything for me), but this is by my money the best thing Zimmer’s ever done. It’s perfectly acute to the pulses and flows of the tone dictated by the visuals and sound effects, restrainedly unnerving and desperate, when it’s not squawking in anarchy.

But the true star of this picture isn’t the withering photography or the mannerless acting (which I’ve barely mentioned due to the splendour and aptitude of the production), it’s the sound mixing. Stuka dive bombers piercingly shriek as they swoop down on troop carriers and bustling beaches, the ships groan with horrifying precariousness as they slog through u-boat territory, the coughs and splutters of wounded boys practically transcend mediums to muddy the screen. Watching it on 70mm film at the IMAX, it’s more an audio-visual exhibition than a film; severely visceral, consumptive and, well, cinematic. You could close your eyes and still map out Dunkirk’s emotional contours.

In turn, the intensity of the drama also accentuates the intensity of the humanity – bravery or cowardice, rationality or folly – which underscores every action and decision our characters make. Everything has a consequence, and everything feels. It’s a film about minor detail in an immense landscape.

The denouement then, and real triumph, of Dunkirk – and what really distinguishes it from the turgid war film template – is how it drags our attention away from individual heroism towards collective action, the unshowy and seemingly arbitrary sacrifices that when collated together can tilt the direction of the greatest conflict in modern human history.

Since last June, the notion that there still exists a shared, unifying set of British values has become absurd. The levels of atomisation – culturally, politically, and economically – in Britain today can dismay, yet Dunkirk submits that our most quintessentially British characteristic isn’t our stalwart stoicism, our propensity for queuing, or our affection for jam sandwiches and tea (although it features all of these, including the jam sarnies), but our unremarkable, humble compassion. As Mr. Dawson and his son sail on against the dread of war they marry thoughtfulness with competence, charity with resolve, humanity with sacrifice: and we’re reminded of those thousands who donated to the Grenfell victims: who supported the families suffering after the Manchester attack: who every day volunteer at food banks, asylum seeker shelters, health clinics, community centres, all in the purpose of helping Britain become a better, kinder place. We may have lost our communal identity, but Britain still cares now as we did then.