I’ve always had a fairly fluid relationship with time.

Just ask anyone who’s ever suffered the misfortune of trying to manage me.

Watches feel more like a handcuff to me, rather than a handy way to tell the time… which may explain why I’m always late for everything.

But with Dunkirk, Christopher Nolan has taken the relentless ticking of time to dramatic new heights.

Based on our country’s greatest military defeat, Dunkirk tells the World War Two story of how Britain managed to rescue more than 300,000 soldiers from the beaches of France.

Nolan has assembled an impressive ensemble cast featuring some of Britain’s finest acting talent, such as Tom Hardy, Cillian Murphy, Mark Rylance and Kenneth Brannagh.

There’s also some kid who used to be in one direction.

But as we follow these different characters through their own Dunkirk journey – on air, land and sea – their names become lost, even unimportant, as they come to represent the collective experiences of soldiers, sailors and pilots rather than individuals that we’re supposed to remember and even identify with.

In the absence of a typical leading role, Hans Zimmer’s incessant score emerges as Dunkirk’s constant presence.

Inspired by the relentless ticking of a clock, Zimmer’s music rhythmically ratchets up the tension as the varying threads of army, navy, RAF and even civilians collide in a dramatic race against time to save some 400,000 soldiers from being captured by the Nazis.

Or worse.

As you’d expect from the best British director of his generation, Nolan has seamlessly stitched together Dunkirk to offer a glimpse into this desperate survival story as Britain miraculously escaped a crushing defeat to the nazis that would have left us defenceless against any German invasion that would have surely followed.

But for all the merits of Dunkirk as a film, its most important role is in telling a story from our past that is in grave danger of being forgotten.

As time marches ruthlessly on, people are forgetting valuable lessons that should never be forgotten.

Or worse, as insidious politicians like Nigel Farage and Boris Johnson attempt to hijack our past for their own nefarious means, so they can write a future that benefits themselves.

The sad thing is, this is working.

The truth of Dunkirk is we were incredibly lucky to escape at all – Winston Churchill naively deployed the British Expeditionary Force [BEF], now known as the British army, to central Europe where they were routed by Hitler’s superior, more organised forces.

Cut off from other allied troops, the BEF were literally trapped between a nazi devil and the deep blue sea – until Hitler surprisingly ordered his armies, who had surrounded allied soldiers, to halt for three days.

The reasons for this delay are open to debate – what isn’t is that without this Churchill wouldn’t have been able to launch any kind of rescue mission at all.

I know this because I spent six months working for the Imperial War Museum this year, writing articles to celebrate its centenary last May.

It’s why I know that Dunkirk was a victory for allied forces rather than just Britain, as thousands of French and Belgian soldiers amongst others gave their lives to hold off nazi troops from destroying Britain’s army and forcing our surrender.

It’s why I know that the most successful squadron in the subsequent Battle of Britain was predominantly made up of Polish pilots who had found a way to get to England after Poland had been invaded by Germany, so they could carry on fighting the nazis.

Defeating the greatest evil modern civilisation has known was not a victory for Britain, it was a victory for Europe – and to a lesser degree America – working together against a common enemy.

I recently learned that my grandfather was at Dunkirk – I knew that he’d fought throughout the Second World War, but watching Nolan’s latest film with this knowledge was a sobering experience.

The things he and his generation of men and women must have seen and lived with… I’m lucky enough to never have experienced anything like this.

But the lessons these people learned – and fought for, and died for – are being forgotten and trampled upon by opportunistic politicians who pretend to be patriots, but are anything but.

I sometimes wonder what my grandfather would make of the time we live in… I damn sure know what he’d have made of the politicians of our time.

If Dunkirk helps people remember the sacrifices of the past, and the truths behind this that right wing politics try to obscure, I doubt a more timely film will have been released this year.

Jonathan Campbell