A utopian dream of a new urban community, built here in the 1970s, had slowly degraded into a poor neighborhood plagued by aimless youth before it finally burst into flames three weeks ago. After Karim Boudouda, a 27-year-old of North African descent, and some of his friends had robbed a casino, he was killed in an exchange of automatic gunfire with the police. The next night, Villeneuve, a carefully planned neighborhood of Grenoble in eastern France, exploded. A mob torched nearly 100 cars, wrecked a tram car and burned an annex of city hall. The police, reinforced by national riot police, responded in 'Robocop' gear, with helicopters flying overhead and television cameras in place, and made a number of arrests in a series of raids. President Nicolas Sarkozy, battered in the opinion polls, quickly seized on the event as a symbol for a new campaign to get tough on immigration and crime. On July 30, about 10 days after the riots, he flew to Grenoble to make a fierce speech condemning violence, blaming 'insufficiently regulated immigration' that has 'led to a failure of integration.' He vowed to deny automatic citizenship at 18 to French-born children of foreigners if they are juvenile delinquents. He said he would also strip foreign-born nationals of French citizenship if they had been convicted of threatening or harming a police officer, or of crimes like polygamy and female circumcision, which are widespread in North Africa. 'French nationality is earned, and one must prove oneself worthy of it,' he said. 'When you open fire on an agent of the forces of order, you're no longer worthy of being French.' Villeneuve, or 'new city,' emerged directly out of the social unrest of the May 1968 student uprising. People committed to social change, from here as well as from Paris and other cities, came to create a largely self-contained neighborhood of apartment buildings, parks, schools, and health and local services in this city of 160,000 people, at the spectacular juncture of two rivers and three mountain ranges at the foot of the French Alps. Villeneuve was a careful mixture of private and public housing, including subsidized apartments for low-income families, with branch offices of city hall and a neighborhood corporation that would take care of public spaces while providing residents construction, plumbing and painting services at moderate costs. 'In the spirit of '68, we made a bet, that with this social mixing we could help everyone advance,' said Jean-Philippe Motte, a longtime city councilor from the political left. 'Of course, that was 40 years ago.' Villeneuve began to deteriorate in the 1990s, with more poverty and joblessness, especially as immigrants from former colonies of the Maghreb and black Africa altered the original social and economic balance. Some of those who could afford to leave did so, and a population of nearly 16,000 dropped to the current 12,000. Three of the original nine schools closed. 'A lot of the middle class left and pulled kids out of school,' said Abderrahmane Djellal, 45, a deputy mayor who works on job training and runs a youth association called Cafe Creme. Djellal, who arrived from Algeria at the age of 10 and graduated from the University of Grenoble, says he is a product of Villeneuve's good years. 'I came from a big, modest family' of eight children, he said. 'We went to the local schools. It was an environment that helped me, but now it fails people. There is a social and cultural marginality that has instituted itself.' Quiet during the day, the open spaces of Villeneuve were increasingly taken over at night by bands of unemployed youth whose parents came here from the Maghreb. Now there are drugs and arms, and a sharp increase in cases of personal aggression and robbery, said Vincent Manuguerra, who lived here until 1996 and still works here. 'They've appropriated the public spaces,' he said. 'The kids want money now, and they don't care how they get it.' After the riots, Sarkozy's interior minister, Brice Hortefeux, fired the local police chief. His replacement will be Grenoble's third in three years. Michel Destot, Grenoble's Socialist mayor, said the firing was unjust. Grenoble needs more police officers, he said, having lost 17 percent of its force since 2002, after Sarkozy, then interior minister, sharply reduced beat policing. The mayor said Sarkozy was using Villeneuve for political ends, when the problems are deeper and national. 'We're in one of the so-called great countries of human rights,' he said, but Sarkozy's pledge of 'going to war against criminals' really means 'going to war against an ethnic community, against a neighborhood,' which Destot called 'insane.' 'The role of political leaders is, on the contrary, to bring people together, to make peace in a certain way,' he said. His criticism was echoed widely on the left, but the Socialist Party has had little concrete to say, with officials refusing 'to be dragged into the trap' of a security debate. Party leader Martine Aubry simply issued a statement saying that Sarkozy 'hurts France and its values with special laws that are unfair and potentially unconstitutional.' The Sarkozy push on security appears to have been well-planned, ready for the spark provided by Villeneuve and another attack on the police in St.-Aignan after a Gypsy was shot dead during another car chase. Sarkozy has campaigned as tough on crime and famously called suburban rioters in 2005 'scum.' Hortefeux brushed off the criticism. 'We're waging a war against insecurity,' he said. 'We're on the side of the victims and we have only one enemy: the crooks.' Opinion polls indicate that the Sarkozy measures are broadly popular in the country. To Yohann Samba, 18, the unrest and the government's reaction were not unexpected. 'We knew this would happen,' he said, lounging by the Villeneuve tram station in carefully chosen athletic clothing of black and gray, mixing Nike and Adidas. 'There is no communication with the police,' he said. There are big problems here, 'and they will get worse now. They're not trying to understand.' Born here of Congolese parents, Samba will study law in the autumn. Sarkozy's tough speech, he said, 'is aimed directly at me, but it doesn't shock me.' Djellal, the deputy mayor, agrees with Sarkozy that the state 'must fight the underground economy, the drugs and arms.' 'But where I can't follow Sarkozy is when he goes too far and says it's the fault of 50 years of immigration,' he said. His father won the Legion d'Honneur fighting for France in Indochina. 'For us, it's insulting,' he said. 'A president must make a republic for everyone, so everyone has the chance to participate in the pride of France.' 