Suite Française, by Irène Némirovsky, trans Sandra Smith

When I began to read Suite Française, excitement mingled with a kind of trepidation. If young writers arrive trailing premature clouds of glory, a critical deflation of the fledgling genius does no harm, and may even do some good. But what about a posthumous novel snatched from oblivion 60 years after its author's death in Auschwitz, then hailed in France as a work so great that in 2004 one leading prize changed the rules to allow it to win?

Here, a reverential chorus had agreed, was the miraculously rescued War and Peace of the French collapse in 1940 and the Occupation - or rather, two-fifths of the planned epic. Born in Kiev to a banking family, living in France since 1919, Irène Némirovsky became a bestselling novelist in the Paris of the 1930s, fled with her two daughters to the country west of Dijon when the Germans came, was deported to Auschwitz as a stateless Jew in August 1942, and promptly murdered there.

Her notebook, preserved by her daughter Denise through harsh wartime years of flight and secrecy, then unopened for decades, turned out to contain not the presumed diary but two completed sections of a five-movement fictional symphony that would - as an author's note suggests - deliver a grand, unsparing funeral portrait of France in defeat, "as it loses its honour and its life". Such a melodramatic back-story carried its own risks: of a wave of pious hype that would salute not a book but a life, or an era, or own time's endless capacity for kitschy self-righteousness.

I need not have worried, and neither should you. Suite Française, even in this truncated form, is a magnificent work that its readers will cherish for as long as they still care about the art of fiction or the history of Europe. Even more astonishing, given its heroically large themes and the desperate circumstances of its composition, this is no gloomy elegy but a scintillating panorama of a people in crisis - witty, satirical, romantic, waspish and gorgeously lyrical by turns. Every page shines both with a ravishing delight in the surfaces of life, and a profound empathy for the souls of its characters, that raises it to the rank of the Russian and French masters whom Irène Némirovsky summoned to watch over its creation in the fields and woods of Issy-L'Evêque, with Germans tramping past her every day.

And since it will (and should) matter to readers presented with high claims for a novel in translation, let me say that this terrific version by Sandra Smith seems - after close comparison with the original - virtually never to botch a phrase, mangle a sentence or miss a nuance.

Another of Némirovsky's fascinating notes on technique (reproduced in an appendix here) underlines that "the historical... facts must be only lightly touched upon, while daily life, emotional life and especially the comedy it provides must be described in detail". What comedy, and what detail! The two finished movements, "Storm in June" and "Dolce", have entirely distinct moods. "Storm" shuffles several groups of characters in a thrilling, pacey and almost shockingly funny social montage, as the German invasion prompts Parisians rich and poor, noble and (most often) venal, to flee the city and seek refuge wherever they can find a bolthole, from grand hotels to rural farmsteads.

The stuffy, snobbish Péricands, led by a holy but ruthless matriarch, look after their fine linen but manage to lose an aged parent on the way. Gabriel Corte, the sybaritic Establishment writer with his bored mistress and a life "as brilliant, luxurious and disciplined as a ballet", skulks in a plush Vichy bar with his well-connected cronies to plot their compromise with the Nazis' new order. Meanwhile, the long-suffering Michauds - the bank-clerk couple who provide a still moral and human centre in this tempest of surrender and cowardice - search for their soldier son and curse "our bad luck to be born in century full of storms".

Everywhere, the writing hums with energy and mischief, and sparkles with a sensuous finesse, from the early-summer smells of panicking Paris ("chestnut trees in bloom and... petrol with a few grains of dust that crack under your teeth like pepper") to a breathtaking scherzo of a chapter in which the Pericands' cat Albert goes hunting in the warm night, as primevally vicious as the invaders, and then returns "purring like a kettle on the boil". As in Zola or Turgenev, Némirovsky recruits the shifting tones of nature and weather to counterpoint human passion with dazzling flair and precision.

For "Dolce" - no longer driven by the "cinematic" rhythms of "Storm" - the pace slackens, the tone softens, but the emotions deepen. In occupied Bussy (clearly drawn from the author's Issy hideaway), the still-polite and nervous German conquerors get to know the women of the town and stir a range of feelings - from loathing to lust to wait-and-see respect - that Némirovsky captures with unflinching honesty. Brilliantly, she also shows how defeat brings into the open all the toxic hatreds between classes, families and generations that have festered in this "affluent but primitive" backwater of la France profonde. In the wings, the peasantry murmur and plot the early stages of Resistance: we know from her notes that the French fightback would have come to the fore in the novel's third section, "Captivity".

Centre-stage is taken by the wealthy Angellier family in their chilly town-house. Lucile, an unhappy wife whose boorish husband has been taken prisoner and whose mother-in-law simmers with reactionary regrets, slips into a Platonic affair with a billeted German officer, Bruno. Their liaison ("like stroking a wild animal") inspires some of the finest passages in a novel stuffed with innumerable treasures. On one rainy, windswept spring afternoon ("so tender, so strange in the middle of war"), he plays Scarlatti to the "great mournful creaking of the cedar tree in the garden outside". Here, all the erotic and artistic grace and wisdom of old Europe come to rest in the "slim white hands" of one of its gravediggers. And Lucile thinks: "This is for ever".

Mere months after she wrote these and other unforgetttable scenes, the Germans to whom she extended all her history-defying gifts of empathy would slaughter Némirovsky along with the rest (so the Nazis hoped) of European Jewry. "Dolce" ends with the regiment's fête champêtre in the château grounds breaking up, as news of the invasion of the Sovet Union arrives in June 1941. Another radiant tableau, this finale reads as if written by some august historical novelist enlisting all the forces of hindsight and perspective half a century after the event. It was scribbled, in haste and at risk, in the eye of the storm.

When the cultivated Bruno von Falk finally embraces Lucile and starts to make love to her on a perfect summer evening, desire fades as she feels only "the cold buckle of his uniform pressing against her chest, which froze her to the core". As on every page of Suite Française, the scrupulously exact image carries all the emotion of the scene - both personal, and historical. Soon, those cold uniforms would destroy Némirovsky.

When Lucile sighed that her afternoon of serene bliss was "for ever" - " éternel" in the French - her creator knew full well that the hope was utterly false. False, that is, for herself, and for her characters; but not, I think, for this wonderful book.