America has never celebrated Thanksgiving in more poignant circumstances

A journey this week to the traditional heartlands of New England revealed that, far from having been extinguished, the flames of human hope and love are burning brightly still

The story starts with a car, a key, a New England village and hundreds upon hundreds of turkeys. The scene is Thanksgiving, the festival by which Americans define themselves. Everyone goes home. Friends with no families find a hearth for the celebration dinner. They make a national gesture to their history and the first settlers' harvests. The fires are lit, and they act out Abraham Lincoln's proclamation of 1863, which decreed that on every last Thursday of November people should step outside themselves and give thanks for the prosperity and power that had come their way. Though the Civil War was on, he added "peace" as a blessing they should celebrate. Every year, it's the moment to catch America looking at itself. And this year, you might think, the picture is vivid and clear.

The story starts with a car, a key, a New England village and hundreds upon hundreds of turkeys. The scene is Thanksgiving, the festival by which Americans define themselves. Everyone goes home. Friends with no families find a hearth for the celebration dinner. They make a national gesture to their history and the first settlers' harvests. The fires are lit, and they act out Abraham Lincoln's proclamation of 1863, which decreed that on every last Thursday of November people should step outside themselves and give thanks for the prosperity and power that had come their way. Though the Civil War was on, he added "peace" as a blessing they should celebrate. Every year, it's the moment to catch America looking at itself. And this year, you might think, the picture is vivid and clear.

Yet there is nothing simple about it. The pulse seems easy to find at first, then nearly impossible. The beat comes and goes, dips away before coming back stronger than ever, then slips off again. In the last 10 weeks or so the cataract of private emotion has become a public display, and almost an addiction for many who say that their feelings are so powerful and unexpected they've had to flood out. Sometimes it has seemed an involuntary spasm, beyond anyone's control. And what lies underneath is hard to understand. For all the characteristic openness that has stamped the past 10 weeks, many Americans are still unsure of where those feelings will take them. What is certain?

So to New England, with certainties that are surely still secure. The townships in the hills still resonate with the physical echoes of their history; they've resisted more urban desolation than most; Yankee families still speak of little patches of land grabbed happily from George III; many people still carry a route map of the wars of independence in their heads. Tamworth, New Hampshire, is like that. It lies in a great granite bowl just south of the White Mountains, which climb to more than 6,000ft, and the hamlets round the township have looked much as they do now for generations. This place is steeped in its own history. This is where it must be easy to touch part of America.

The car helped. By one of those embarrassing muddles it is easy to blame on a new-fangled locking system, but which can't be concealed by such a threadbare excuse, a key found itself locked in a boot. The doors were secure. The car was impenetrable, and plans began to dissolve around me. I had a date at the turkey farm, a mile or so away. I would be late for the rehearsals for the town play, in the little theatre. The phone was in the car (though, unknown to me, already rendered useless by the granite mass of the hills around). Tamworth then revealed itself.

My friend of 20 minutes, Peggy Johnson, hoisted the storm cones. From one of the two stores – not the other one, which is called The Other Store – came a key for a similar looking car. The key, of course, was sitting in an unlocked car – a standing rebuke to the suspicious visitor from London. It didn't work. But Dan the policeman was on his way. Meanwhile we went into the town hall, outside which the stricken car sat, and inside which we passed through a door bearing the legend "Town Clerk and Tax Collector". This is where the town government resides, under three – only three – "selectmen", chosen each year by the town meeting at which Tamworth turns itself for a day, like many places across the New England states, into a Yankee Greek city state, sorting everything out in a cheering moment of direct democracy. A new selectman joins the town government, to replace the one whose three-year term is over. It goes round and round, as it has since sometime in the middle of the 18th century.

Fascinating, but not the answer to the armoured car, which had now turned into a safe-cracker's nightmare. Dan Poirier, the policeman, had come with a bendy piece of plastic with which he was attacking the windows. A minor crowd was gathering at the street corners, eddying round the scene. Scott, the forester, came along. He had various bars and gadgets in his truck, but nothing that wouldn't leave Dollar Rent A Car wanting a large refund.

The pace was quickening. The play rehearsal was about to start. A teacher arrived. He was Richard Posner, from Essex. He and his wife run a little alternative school in Peggy's house. The children coming to the play rehearsal milled around him. "Why here?" I asked him. "Look around you. Why not?" he said. The kids wondered how to get into the car. They poked and prodded along with Dan. The shop door jangled as people came out to look. Cars slowed down even more than usual as they tootled along Main Street. The librarian was wheeling a cartload of books, packed in old whiskey boxes, back from the store to her renovated building (The Cook Library, 1895) and she paused to sympathize. The bell on the Congregational Church, which makes all its white boards shake once every hour, began to boom. There wouldn't be time to get the turkeys before the curtain went up at the rehearsal.

Then came Jerry, summoned from a garage not far away. He opened what seemed to be a burglar's box of dreams. Coat-hangers, plastic rods, wire of all sorts, wooden plungers and sticks, bits of string and implements that looked as if they had been a job lot from the last dentist to leave Tamworth now lay before us. He began to fiddle and jiggle, and Dan the policemen went off on his rounds, tactfully avoiding the skilful denouement. Word had spread. When Jerry sprang the door and the alarm hooted for several minutes to inform the whole of Tamworth that the deed was done, it was as if the whole thing had been a rehearsal for the rehearsal.

We went to the turkey farm, on Turkey Street (where else?), where 640 corpses were waiting to fill the town fridges, and then set off for the theatre, pausing only to hear the story of a wild mink that had yesterday savaged two innocent ducks (before their proper time came at Christmas) and to be told all about the town doctor who died without issue, having led a quiet life like his doctor father before him, and was found to have left $16m, a good portion of which came back to the town in new building, white paint and community enterprises, one of which was the refurbishment of the theatre (1931), where even now the children of Tamworth were being transformed into East End urchins for the annual production of A Christmas Carol.

They were sorting out the door to the office of Scrooge and Marley. There was a moment to think. Tamworth had revealed itself already. It was a warm and confident community, a close and easy place where after an hour or so in the soda fountain at The Other Store or on the creaky boards of the lounge in the Tamworth Inn you could sense a genuine tranquillity. The woodsmoke rose straight into the sky, the last of the fall leaves crackled underfoot, birds skittered along the river bank, and from Turkey Street a procession of carcasses made their dignified way to the kitchens of the townsfolk, ready for Thanksgiving Day itself, which had turned the roads coming north from Boston and west from Portland, Maine, into a crawling pilgrimage home.

Then, a surprise. I had talked to Peggy of 11 September, of course. Katie at The Other Store had a cousin in the World Trade Centre. Everyone knew someone who knew someone. People had been part of the national trauma. She said: "You know, I wonder if we've moved on too quickly." It was a piercing shaft. Her tone was poignant, wondering if human beings were getting too good at managing the recovery from horror.

There's been much talk of a country that won't be done down by terrorism. The ubiquitous wayside pulpits urge resolution in the face of attack (though one just outside town says "Pray For Our Enemies") and the natural urge has been to celebrate community and democracy – the business of not being "done down" by terrorism. But moving on "too quickly"? Under the confidence of places such as Tamworth, which especially at Thanksgiving time can cling confidently to the old ways and values that endure down the generations, there may be a fear that the deep shocks of New York and Washington can be absorbed almost too efficiently, at least by adults. For children it is different. One 10-year-old put it like this: "It's scary. I don't know why. It just is." Her friend, 11, said she still wondered how it was that people just like her parents in other countries could do what they did to those people who died. They speak openly about the apprehension that, among their parents and grandparents, is often concealed.

Peg Custer is the rector of the little Episcopal church, St Andrews-in-the-Valley, and she gets glimpses of that apprehension. Getting her turkeys ready for the drop-in Thanksgiving dinner in the church hall, she says she's aware of deep anxiety. "People say to me, as a priest, that they have a strong sense of the unknown and it scares them. I've had to counsel many people with real fears." You can't have a conversation for more than a few minutes without evidence of that deep uncertainty breaking the surface. Christine at the Tamworth Inn: "It's been a bad, bad time for every one of us." Irene at the Whittier Store: "I just hope it turns people back to community and family. We need it. There's been awful sadness here. Awful."

Under the bubbling bonhomie of Thanksgiving lies a lake of anxiety. Peggy's fear about dealing with it too easily, too quickly, is really a concern that its presence will not be acknowledged openly enough. Its existence can't be denied; but the pressure to return to a triumphant normality as evidence of victory over evil might cause it to be pushed out of mind as a deliberate act of defiance.

On the edge of town is a higgledy-piggledy electric sign, the letters spelling out a birthday greeting to Robin (26) and also announcing to passers-by that "We Will Prevail". You catch there the ambiguity of the moment. Let's carry on as before; but there's a war on. As the families of Tamworth lit their candles and drew together at the festive table, there was no escaping the truth. Take the Watkins clan, clustering together at their ancestral cabin on Lake Chocorua, under the witch's hat of the mountain where the Indian chief of that name flung himself from the peak to deny the advancing white men his scalp, and cursed the valley below where they say nothing grew for a generation.

This table was Thanskgiving at its best. Grandparents, children, aunts, uncles, cousins, friends, a student from Beijing studying nearby and falling in love with New England, two Nepalese friends, a German student, an in-law from Bradford, having fun – but talking about the war too. Where would it end? Was it possible, John Watkins said from the head of the table, that good might come out of it all? That a greater understanding of the outside world would come to Americans? They agonised, even as the festive bird and the squashes and relishes and special family recipes for onions and green tomatoes did their rounds. This was a celebration with a melancholy undercurrent breaking the surface.

Down on the lake, where ee cummings and Henry James both came for escape, a loon hooted across the water. The night drew in. Lights sparkled in the trees. At the Beechers' house the family celebrated, but a grandfather who remembered arriving at Berchtesgaden as a GI to clear up after Hitler wondered if the grandchildren playing at his feet were doomed to experience another century of war.

And not far away, at another blazing log fire in another cabin in the woods, Admiral Ralph Weymouth spoke of peace. He first sailed in a US Navy cruiser in 1938, from which he watched bombs falling on Barcelona. More than 30 years later, after Vietnam and a couple of decades of gnawing disillusion, he became a star of Veterans For Peace and still, in his eighties, speaks with the glittering eye of the believer. He describes the Middle East tragedy with a weary familiarity. He talks of a hope that people will emerge from the horrors of 11 September and its aftermath with a newly fashioned commitment to say "Never Again". He doubts it, but he tries.

Everywhere there was a pinprick reminder that behind the celebration was the unknown. At St Andrews-in-the-Valley the diners were asked before raising a fork to name one thing for which they could be thankful that day – the kind of exercise so embarrassing to Europeans and so natural to most Americans. More than one said, with real feeling: "Still being here. Just being here." This wasn't melodrama, but a still voice of reason. Everyone believes there is still much to fear. Anthrax? War? Another attack? They don't know, and it scares many.

Tamworth is itself and not all America – though it has more poverty than the casual glance shows, it has little of the churning despair that shapes some of America – but it exhibits in its own way all that the country is at this moment. In its theatre – "Dickens is better than Neil Simon, for me," says the man playing Scrooge – they romp. By its lakes, they treasure the placid life. In its community, they play. The women, taking their cue from the WI "Full Monty" calendar, have done one of their own, tasteful shots of 12 nudes made decent by branches, flowers, carefully placed babies, an artist's easel and a flute. "I'm June," said Amy Berrier – for that was her month in the calendar – when I went to see her. I almost said that I didn't recognise her with her clothes on, but in Tamworth that has already become an old joke. They've moved on, happily.

But Peggy's nagging worry that too much from this year might be put behind them too quickly is a good and natural fear that can be dispelled. No one has forgotten; no one will forget. Children ask questions; grandparents find ways of avoiding answers; those who work in New York, or whose children are there, have moments when they look out towards the trees away from other eyes. No one knows where this period will take America, on the battlefield or at home. They sense, however, that they are on a journey.

That, of course, has been America's history. You can't be in New England without thinking of Robert Frost, its poet. He speaks of things that last in that landscape and among these people. At the end of "The Bonfire", he writes:

Haven't you heard what we have lived to learn?

Nothing so new – something we had forgotten:

War is for everyone, for children too.

I wasn't going to tell you and I mustn't.

The best way is to come up hill with me

And have our fire and laugh and be afraid.

James Naughtie presents 'Today' on BBC Radio 4