Poverty, unemployment, the influence of criminal gangs - all this lies in core of rioting that erupted in France this week.
But there's one taboo issue that officially colorblind France has been unable to confront: race.
The violence, like riots that spread nationwide for three weeks in 2005, exposed how parts of France have divided along color lines, with blacks and Arabs trapped in the most disadvantaged neighborhoods - like those in Villiers-le-Bel, in the northern suburbs of Paris, where gangs attacked police and burned cars and buildings.
"Among the rioters, the very large majority come from immigrant backgrounds," said Douhane Mohamed, a police commander. "Why? We mustn't kid ourselves: there is a direct link between urban violence and ghettos, and the majority of people with immigrant roots live in ghettos."
France doesn't like to see its recurrent and some say worsening bouts of urban violence through the prism of race or color. Instead, rioters are often described simply as "youths," while poor projects with large concentrations of immigrants are "sensitive urban zones."
In the name of equality, France has so idealized the melting pot that it has made its minorities invisible - on paper at least. France doesn't compile statistics on the foreign-born or their French-born children. France, for example, has the largest Muslim community in western Europe but does not know how many Muslims live here. The number is estimated at about 5 million - though some experts disagree.
Critics argue that being officially colorblind has limited France's ability to recognize and treat the difficulties its minorities face - sometimes because of their color. Immigrants and their French-born children often complain that its harder for them than whites to get work, job interviews, housing, even entrance to nightclubs.
President Nicolas Sarkozy once toyed with the idea of affirmative action but then dropped it before he won the French presidency in May. He won praise for appointing three women to his Cabinet who have roots in north and sub-Saharan Africa. But his toughness on immigration and crime has angered many minority youths.
Sarkozy took a hard line against this week's rioters, dismissing the notion that they were symptomatic of a wider social crisis and instead labeling them a "thugocracy."
The rioters are a tiny minority but sullen anger is palpable in Villiers-le-Bel. Black youths complain that police stop and search them because of their color. They speak of exclusion, of not getting a fair shake, of being treated like foreigners in their own country.
Few residents condone the violence and many condemn it - but no one seems surprised that it broke out. France's projects, many in and outside of them agree, remain tinderboxes that need just a spark to explode.
"Everyone is equal. That is what is written. But behind that is something else," said Hassan Ben M'Barek, spokesman for Suburbs Respect, a group that lobbies for those who live in disadvantaged neighborhoods.
In some such areas of the Paris region, "there are no white French people left in the streets. You can drive around for two or three hours and all you will see are North Africans and blacks. And these are neighborhoods with enormous problems," he added. "Those who have the means to leave the projects are white, and they leave. There's no more ethnic diversity."
It was impossible not to see the violence in Villiers-le-Bel in black and white terms.
The hundreds of beefy riot police officers drafted in, some from as far away as France's eastern border with Germany, were almost exclusively white. The neighborhoods they patrolled were largely black and Arab.
The trigger for the rioting was the deaths last Sunday of two teens killed in a motorcycle crash with a police car. Lakamy Samoura, 15 and Mohsin Sehhouli, 16, weren't wearing helmets and their bike wasn't authorized for public roads.
Police insisted that the crash was accidental, but kids in the neighborhood didn't believe that. The deaths became an excuse for two nights of rioting in which more than 100 police officers were injured, some by shotgun rounds.
Tellingly, neither of the teens will be buried in France, although both were French. Mohsin's parents are taking his body to Morocco; Lakamy will be buried in Senegal, from where his parents emigrated in 1966.
Having a foot in France and another in Africa is something that Maka Sali, a black 17-year-old in Villiers, identifies with. She said she doesn't like taking trips into Paris - which is about 20 minutes away on the train - because she doesn't like the way some whites there look at her.
"I feel like a foreigner," she said. She also said it was "just terrible" that it took the deaths of two teens to thrust the issue of France's poor neighborhoods back to the forefront of the national agenda - as did the riots of 2005. They, too, started when two teens were killed - electrocuted while hiding in a power substation from police.
Some argue that the recurring violence must make France rethink its taboos.
Mohamed, the police officer born in France of Algerian parents, said France should carefully allow research into the proportion of crimes and urban violence carried out by minorities, so solutions can be found.
M'Barek said France needs more minorities in visible positions of responsibility and that affirmative action may be a way to get them there.
Since the violence of 2005, France has earmarked billions of euros (dollars) for programs to improve housing and create jobs in tough neighborhoods. The government says that its newest "equal opportunities" program will be unveiled Jan. 22.
But it was hard to see among the burned out cars and blackened moods in Villiers that much has changed.
"The only thing they (the government) have done is build that police station," said Frank Dosso, a black 16-year-old, referring to a 5 million EUR(US$7 million) police station under construction in Villiers. "But that's not going to last long."
Austria does not intend to expel Russian diplomats because of the spy scandal