Near the tiny hillside village of Moureze in Languedoc-Rousillon there is a roadside memorial.

Beneath a strange, shrouded figure, its hands grasping a sword bearing the Cross of Lorraine, there are 105 names. These were the dead of the Maquis Bir-Hakeim.

When I first saw the edifice I knew a little about those Resistance fighters. They had taken their name from a Free French battle in Libya. They had fought Nazis across southern Aveyron, the Herault, the Cevennes and the Rhone valley. They had been heroic, ruthless and, sometimes, reckless. They had paid a high price. But they had not been the only ones to pay.

Travel a little to the north-east of Moureze and you reach the edge of the Ardeche. Here's another speck of a commune. Labastide-de-Virac is a pretty place, but it is lucky if it has 250 citizens. On the other hand, Labastide still lives. Hameau des Crottes, once nearby, does not.

On March 3, 1944, the SS put to death the 16 peasants of Crottes. An attempt was then made to destroy their handful of houses. This year a memorial was raised in Labastide to mark "victimes de la barberie Nazie", but no-one local has returned to the hamlet in 70 years. The 16 were killed in retaliation for an action by Bir-Hakeim.

France has struggled with the legacies of collaboration and resistance. The "memory wars" are unceasing. How many truly fought back against the Nazis? How many - a better question - truly could? How many greeted their conquerors with obedient zeal? How many tried just to survive? What was the human price paid by those who refused to submit?

Hameau des Crottes is one answer. The murders there, fewer by far than the massacres at Oradour-sur-Glane and Tulle (in the Haute-Vienne and Correze respectively), have only local fame. The peasants were not the Sten-gun wielding maquisards of movie legend, whatever their sympathies. They were slaughtered in reprisal and as a deterrent to Bir-Hakeim.

Travel again, a little to the north-west, and the Ardeche's tangle of rocky hills and gorges gives way to the Cevennes. Here is the Massif Central proper, the heart of France. Despite the arrival of an autoroute at its fringes, this remains a sparsely-populated landscape. If you begin to trace the route once taken by Robert Louis Stevenson and Modestine, that famous donkey, you are close to the small town of Le Chambon-sur-Lignon.

Caroline Moorehead's remarkable book is in essence the story of how a community, or rather group of communities, survived the travails of war with dignity. It is also a tale that gives a larger meaning to Hemingway's macho phrase, "grace under pressure". In Le Chambon, half-hidden on the Plateau Vivarais-Lignon, while Europe succumbed to bestiality and France surrendered its honour, a spiritual grace was achieved.

That, though, is the established legend, an often-old tale. Moorehead does not dispute it, but she shows that even acts of heroism, charity and solidarity are more complicated by far, in their origins and consequences, than we would like to believe. In Le Chambon all of the contradictions of France in wartime existed in microcosm, yet on the plateau household after household gave shelter to refugees, to Jewish children above all. Why was that?

Moorehead is wary of attempts to simplify history and ignore the complications of memory. She is sceptical of those who have tried to render Le Chambon as a parable of non-violent virtue triumphing against the odds, just as she is sceptical of the claims made for and against "the French" under occupation. Hers is a story of nuances, hues, conflicting loyalties, misaligned memories and politicised histories. Yet at all times the essence of something remarkable is kept in view.

How many were saved? As Moorehead writes, in 22 communes and isolated farmhouses on the plateau, "more people, proportionately, were saved than anywhere else in France. Saving was what local people did, silently, acting together, working things out, planning, sharing the burden". She discounts claims that 5000 were kept from the death camps, but believes that perhaps 800 were hidden away, with another 3000 helped to safety in Switzerland and elsewhere. The population of modern Le Chambon barely exceeds 2500.

In the first years after the war, the town's efforts were presented to the world as the triumph of one man, a Protestant pastor named Andre Trocme. This inflexible pacifist, drawing on the old Huguenot and Camisard traditions of the Cevennes, was described as having inspired the entire Plateau Vivarais-Lignon to devote every effort to saving Jewish children. Trocme deserved every honour, but so too did a collection of farmers, teachers, shopkeepers, cafe owners, charity workers and other pastors. Nor was non-violence of itself the key to their efforts.

Trocme was claimed, in part, to assuage post-war French guilt over Vichy, the southern zone given into the care of the aged Petain by the Nazis. Here was a puppet state built on collaboration and the pretence of enduring "values". Worse, Vichy did not merely co-operate with the country's conquerors. It anticipated their whims, exceeded their quotas, and hunted down Jews with more enthusiasm than the Nazis demanded. Vichy, unasked, imposed the yellow star (and much else besides) on its Jewish citizens.

Such was the problem for Charles de Gaulle in his attempts to rebuild national unity: French officials, under no real pressure, had sent trains to the death camps. Police had hunted down children. Citizens, hungry for rewards, had produced a torrent of denunciations. Some of the French had grown rich under occupation. On one reading, the country had disgraced itself.

Trocme, non-violent godly resistance personified, provided a kind of rebuttal. The achievement of Le Chambon, immune to informants, risking all, was proof that "real France" had survived despite everything while the maquisards waged their lonely war. Again, Moorehead denies no-one their due - for all of that was true - but refuses comforting myths.

When the Maquis became truly active in the Cevennes after young men began to flee forced labour in early 1943, for example, tensions rose on the plateau. The armed patriots risked attracting the attentions of the SS to those whose work depended on isolation and secrecy. Trocme the pacifist was meanwhile unsympathetic to anyone who sought to kill.

Some of the children were happy in hiding, meanwhile, but many were not. Most, torn from families, suffered emotional damage. All lived in fear in the heart of a France that had once proclaimed the values of civilisation.

The sad epilogue to a beautifully told story is that the squabbling over what happened in Le Chambon and the surrounding area persists to this day. Who did what, when, how often? Who claims credit for Trocme and who makes competing claims? What, as the last memories dim, was the truth? Moorehead's question is implicit: is there such a thing? The reader is left with another question, equally difficult: what would I have done?