The miraculous evacuation of almost 340,000 Allied soldiers while under constant fire from the advancing German Army has provided director Christopher Nolan with the subject for his most superlative film yet. Splitting the narrative into three strands - on the beach (Fionn Whitehead's teen squaddie), at sea (Mark Rylance's taciturn small boat captain) and in the air (Tom Hardy's clipped RAF Spitfire pilot) - he marshals the storylines into a visceral, compelling whole while providing a quality hitherto mostly absent from his work - genuine passion. It's a colossal, nerve-shredding effort and one where Nolan never puts a foot wrong.
How what Winston Churchill described as "a colossal military disaster" became "a miracle of deliverance" is the complex military and emotional focus of director Christopher Nolan's formidable World War II masterpiece.
It's a story of how the traditional virtues of courage and decency came to the aid of thousands of stranded, demoralised troops and ensured that Britain literally lived to fight another day.
In succinctly conveying the enormity of the challenge faced - the plucking of more than 330,000 battered Allied troops from the French coast under the noses of the German army - Nolan (no stranger to unorthodox time lines) radically employs three intercut chronologies of different duration - one hour, one day and one week - to dramatise the rescue of the hapless British Expeditionary Force.
He opens in suitable striking style with a group of teenage grunts pitilessly gunned down on the streets of Dunkirk with just Tommy (Whitehead) making it to the beach...to join the well-ordered escapees queuing on the wind-swept sand to board what Royal Navy ships are available.
This is where the first timeline - following the plight of a beach-bound troops - kicks in with The Mole the focus of activity...and a Red Cross ship is struck by dive-bombers, necessitating the soldiers to desert their wounded comrades as the stricken vessel slips under the waves.
With the big ship guns redundant, it's up to the (much maligned) RAF in the form of Tom Hardy's masked Spitfire pilot - think Bane channelling Biggles - to neutralise the threat of the Luftwaffe and in his one-hour time segment we witness some stunning aerial warfare with Nolan's decision to eschew CGI paying stunningly visual dividends.
The third narrative thread follows Weymouth pleasure boat captain Dawson (Rylance), a stoic middle-aged father whose crew include his teenage son Peter (Tom Glynn-Carney) and his younger chum George (Barry Keoghan), as their flimsy-looking craft (one of a vast, small ships flotilla) putters the across the English Channel to a fate of which they know nothing save the terrified fears of Cillian Murphy's shell-shocked sunken ship survivor.
Unlike trusted big studio hands such as JJ Abrams or Joss Whedon, Nolan answers to no-one and his intelligently singular vision is justified on every level as he masterfully sidesteps every cliche that Michael Bay or Zack Snyder would stagger into.
First of all, he rises above cheap stunts like the risible superimposition of a love triangle on top of war epics such as Pearl Harbor or Enemy at the Gates and immerses the audience (with little or no dialogue) in the plight of his economically drawn protagonists as they face lethal peril.
It's not all nobility and derring-do - soldiers are denied a place in the line because they're the wrong nationality or even regiment. Yet the overwhelming impression is of small island dignity and decency.
Critical to the enveloping narrative is Hans Zimmer's superlative score which searingly veers from the banshee shriek of a dive-bombing Stuka, to the percussive drumbeat of a destroyer's screw to a subliminally triumphant reworking of Elgar's Nimrod.
Crucially, Nolan combines his customary directorial verve and solid storytelling with a quality we haven't really seen in one of his film's before - passion.
Ultimately, this is an unsentimentally masterful chronicle of a propaganda victory plucked from the jaws of military disaster.
See it on as big a screen as you possibly can.