A year after rioting engulfed this and similar immigrant suburbs across France, the clock and sign marking the entry to the Lycée Jean Renoir are still burned, beyond recognition.

There's a prison-like wrought-iron gate with a guard at the entry, and dismal housing estates tower beyond the school walls.

France is dreading the first anniversary of the start of the rioting tonight. A report by the domestic intelligence agency, Direction Centrale des Renseignements Généraux, leaked this week, says that "most of the conditions which led, one year ago, to the unleashing of collective violence over much of our territory are still there". The Île-de-France region surrounding Paris is "the greatest source of disquiet", it adds.

The violence started in nearby Clichy-sous-Bois when two teenagers, Zyed Benna and Bouna Traoré, were electrocuted in a power substation while running away from police. Rioting spread across the Seine-Saint-Denis department, two-thirds of whose 1.5 million residents are of foreign origin. It took hold in other departments ringing the capital, and eventually reached every large French town and city. Over three weeks, young men, mostly of Arab and African origin, burned 10,300 vehicles and wreaked €160 million worth of destruction. The French government declared a state of emergency for the first time since the Algerian war.

There were government promises of money, housing, jobs . . . Yet little has changed in the banlieues. Indeed, the socialist mayor of Bondy, Gilbert Roger, says the commissariat that is supposed to serve 75,000 people in his and a neighbouring town has actually reduced staff, from 110 to 104 policemen.

Residents of le neuf trois, the postal code for Seine-Saint-Denis, still face discrimination. But among those who reject violence, a new sense of determination seems to have emerged from last year's catastrophe. I am surprised to hear black teenagers condemn the rioters in terms that sound right-wing.

I meet Pattie and Bradley in the canteen at Lycée Jean Renoir. She is from the Democratic Republic of Congo; he from the French West Indies. (English-language first names are popular in French immigrant communities.) "They want money, but they don't want to work," Bradley says of the rioters. "They follow each other like dumb animals."

Pattie joins in. "They don't know how to do anything but burn cars. And they make it harder for the rest of us."

Four 17-year-olds sit on a bench in the courtyard outside, comparing notes for chemistry and physics classes. When I ask whether they fear another explosion in the banlieue, they seem defensive.

"There's no problem here," says Élodie. Then she catches her breath and tells her friends what happened in Grigny, south of Paris, the previous afternoon: an articulated bus and two cars torched by hooded young men in front of hundreds of witnesses; rioters attacking police who came to protect firemen . . .

Élodie's friend Solène keeps insisting that the rioters are a tiny minority, that too much attention is paid to the negative side of the banlieues. "All the same, it's there," Élodie says. "For example, there's a problem with thieves outside the lycée. One Wednesday afternoon, I left school with a couple of friends and they attacked us on the pavement outside, with tear gas. I ran into the guard's office. They took the guys' MP3s and mobile phones." School officials say such incidents occur at least once a week.

THE LYCÉE JEAN Renoir is one of four in Seine-Saint-Denis to have concluded a special tutoring and recruitment arrangement with the prestigious political science institute, Sciences Po, in Paris. The principal, Jean-Louis Tetrel, made similar agreements with the Pierre and Marie Curie science faculty at Jussieu, and Polytechnique, France's finest engineering school.

Ten graduates from Lycée Jean Renoir have been admitted to Sciences Po in the past three years. The university programmes are a tremendous morale-booster to teenagers who would otherwise have no opportunity to undertake such studies.

"If you do an atelier [ as the special preparatory tutorials are called], you've got the same chance as anyone else," says Élodie, "the same chance as the rich kids in Paris."

"I am not a victim," says Fatimata, a proud young woman from the Ivory Coast who wants to become a lawyer. "If my father was a government minister, I wouldn't be in this school. But I'm very ambitious."

What makes the difference between these four lycéens, with their hunger to succeed, and the young men who burn cars and fight cops? "Parents," says Élodie. "You get to an age where you become conscious of your actions and your responsibilities," says Fatimata, more thoughtfully. "I think it's around age 16." Kevin, from Cameroon, attends the atelier for the science faculty at Jussieu. "I live in the housing projects in Saint-Ouen," he says. "The police come in there a lot. My older brother Edgar used to be like the people who burn cars, when our mother was unemployed. She works as a care-giver now and he's changed. He's studying to be a nurse."

Because French law bans symbols of religious belief, a principal's job in the banlieue includes persuading young Muslim women to remove their headscarves, and Sikhs their turbans - as well as reminding students to look out for the "predators" outside the iron gate.

A dyed-in-the-wool, secular French Republican, Jean-Louis Tetrel calls the recent observance of the fasting month of Ramadan by a quarter of his 1,800 pupils "a scholastic disaster". But his biggest problem, says Tetrel, is "the fear of effort" that afflicts about a third of his students. "They simply don't realise that their success depends on the amount of effort they make," he explains. "They come here as if they were going to the chiropractor, passively. It's a general attitude towards life. It slows everyone down; the teachers feel they're treading water."

Politicians, and even the above-mentioned intelligence report, blame media coverage for stoking last year's riots and for running the risk of provoking new unrest. "We're sickened by the way the media are orchestrating the anniversary of the riots," Tetrel says. "The media invented this anniversary and it's just one small step from invention to programming. They turn local incidents into national and international events."

In Bondy, you hear the constant hum of half a dozen motorways that chop the town into pieces of vacant lots, boarded-up buildings, associations and employment agencies. The architecture is a jumble of 19th-century brick and 1970s urban blight. A carload of young men wearing Hallowe'en masks speeds by, blaring loud music. There are crumbling concrete benches and a brave attempt at landscaping around the Stalinist bunker of a town hall, inaugurated in 1981 by the widow of Salvador Allende.

Mayor Gilbert Roger was born and raised here. A former schoolteacher, he recalls the arrival of the pieds-noirs from Algeria in 1962, when he first tasted couscous and avocados. There was more hope in those days, Roger says.

"People weren't rich then. But they thought they could work their way up and out."

Roger married a Polish immigrant. His blonde daughters have told him they want to leave le neuf trois because of the stigma attached to the address.

IN THE EVENT the violence starts again, Roger had disused cars removed from his town. The interior ministry has recommended other measures: emptying rubbish bins in the afternoon, so rioters won't set fire to them, opening youth centres at night, to keep young men off the streets, and staging "festive manifestations". The municipality holds a concert or show every month, but Roger scoffs at the right-wing government's advice: "Nothing would be worse than telling our population: 'We're afraid of you, so I'm going to arrange a circus to distract your attention'."

Since last year's riots, a taboo against physical violence has fallen. "Before, they stole your handbag. Now they steal your handbag and beat you up," Roger explains. "The gangs are more active.

"I refuse to talk about an anniversary," the mayor continues. "It is much too serious an event. I've been holding public meetings, and I don't sense anything bubbling away - except when there are microphones and cameras around. Unfortunately, if you keep saying something will happen, at the end of the day, it does."

France's future policy towards the banlieues will depend on who wins next year's presidential and legislative elections. Roger campaigns for Ségolène Royal, the leading socialist candidate. "If [ the right-wing candidate and interior minister Nicolas] Sarkozy wins, the confrontation [ between rioters and police] will continue," Roger predicts. "Because we'll be stuck in this strategy of cordoning off the banlieues. But if Ségolène wins, the notion of respect and a just order will prevail."

I put the question to Mohamed Hamidi, a teacher whose Algerian parents were among the first to settle in Bondy in the 1950s. "The mood is less tense when the left is in power," he says. "It's all 'peace and love' then. They kiss us instead of beating us with truncheons, but our problems don't get solved. The left made big mistakes, like never appointing any minister from the minorities."

Hamidi has taken over the "Bondy Blog", which was started by a Swiss newspaper during the riots. Yahoo France has paid him and fellow bloggers €40,000 to "cover" the French presidential election, a project they will pursue with lycées involved in the Sciences Po project.

During the riots, the Swiss journalists lived in a flat in the housing projects in Bondy. "There were incidents from the beginning, always the same youths, who drank or smoked too much [ hashish]," Hamidi admits. "They tried to break the door down, used tear gas, broke windows. The journalists thought [ the youths] wanted to steal their equipment."

But for Hamidi, the project was worth it. "A little aggression was nothing compared to what it brought to us," he says. "It's been extraordinary. A real eye-opener." Like everyone I meet in Bondy, Hamidi swings between pessimism and hope. "There's great energy here," he says. "For every 10 people who burn cars, there are 990 who want to go to school, who want to work. But it's true that other people look at us differently now, with new fear."