Go, Sarko! If the new French president does not succeed, things will get horribly worse.

THE French Revolution having taken place only two centuries previously, Chou En-lai famously remarked that it was too early to tell what its effects might be. A fortiori, it is too early only a few days after Nicolas Sarkozy's victory in the French election to say what that victory means. One thing is certain: It means something.

The rioters in the Place de la Bastille agreed. What they feared was that Sarko, as he is known to both his friends and his enemies, is in reality what he has all along presented himself as being, a man determined to change France. One of the ironies of the election was that the conservatives wanted change, while the liberals wanted everything to remain the same. And there is nothing like the prospect of change in France to spark a riot.

It is instructive to compare Sarko's dignified and decent statement after his election--that it was important for everyone to respect Segolene Royal because millions of French people had voted for her--with the rioters' contorted faces of hatred. Like Mrs. Thatcher, Sarko evokes hatred completely disproportionate to anything he has done or might conceivably do. It is his ideas that are hated and feared more than the man himself.

Oddly enough for a man whose election immediately resulted in a riot, Sarko is what stands between France and real, serious social upheaval and violence. For if nothing changes, the situation will degrade further, until a much greater explosion becomes inevitable; and if Sarko cannot make the necessary changes, no one can.

The gravest social problem confronting France is that of young Muslim men of North African descent in the banlieues, the urban wastelands that surround many French towns and cities, particularly, of course, Paris. The nearest analogy that I can draw is to the townships of South Africa under apartheid, though the level of hatred is probably greater in France than it was in South Africa. Of course, the level of hatred is not necessarily proportionate to its justification, and clearly the French state is not remotely comparable with the South African; but many other factors lead to hatred, among them the absence of self-respect. When Sarkozy called the mob la racaille, they were angry because they knew he was right. No one likes to think he is totally expendable and likely to remain a parasite forever.

At the time of the 2005 riots, no one thought to ask the women of the banlieues what they thought: whether les jeunes were heroes or villains, oppressed or oppressors. The French state, in its response to the riots, made the elementary mistake of pressuring insurance companies to pay compensation (which they were not legally obliged to do) for the burned-out cars, thus missing an opportunity to create tension and opposition in the banlieues between the law-abiding and the law-breaking. If car owners are to be indemnified against arsonists, what reason have they for despising the arsonists?

Sarko is the first serious politician in France for a long time to understand that the enforcement of law is not authoritarian, but rather a precondition of freedom. This not-very-difficult thought has been unpopular among the French intelligentsia for a number of decades, and for several reasons, some of them understandable. French decolonization, from Madagascar to Vietnam to Algeria, was hideously violent; the memory of the milice during the Second World War still, justifiably, causes shame. But the fact that authority has sometimes, even often, been abused does not mean that there is no need for authority--that we can do without it. As anyone knows who has visited parts of towns or cities where the public authority has withdrawn or been pushed out, psychopaths rule; and it is the poor, not the rich, who are the victims of their criminality. Even in Clichy-sous-Bois, one of the worst areas of France, where all the trouble started in 2005, Sarko won 38 percent of the vote. I wouldn't mind betting that many more than half the 38 percent were women.

Allied to his insistence on the enforcement of law as a precondition of improvement in the banlieues is Sarko's belief in the urgent necessity of a more flexible labor market. Nothing integrates people like work, and any French plumber or carpenter will tell you why so many young people find it difficult to get a job in France: An employer is expected to be as much social worker as boss, and an employee, once hired, cannot be fired except with the greatest difficulty. Best, then, to avoid the difficulty and employ no one or as few people as possible.

Two days after Sarko's election, the unions threatened strikes if he tried to reform without their agreement. The problem is that they don't want any reforms. Their members like the situation in which one man's job is another man's unemployment, and in which it is possible to retire at the age of 50 on a generous pension to be paid for by future generations (the French national debt has doubled under Chirac--apres lui, le deluge). The language of general interest in the mouths of French trade unionists is a mask for group privilege.

Assuming that the forthcoming elections to the National Assembly do not hamstring Sarko from the outset of his presidency and saddle him with a government opposed to all his plans, there is no way, other than by doing nothing, in which he can avoid conflict with powerful sections of French society. France is a land of fonctionnaires, bureaucrats with the power to obstruct; of well-organized workers in vital services; of intellectuals virulently opposed to what they call "savage liberalism," that is to say economic competition of any kind; of farmers who depend upon subventions for their survival. All are prepared to go to the streets and create mayhem, block roads, and cause maximum inconvenience in defense of their collective privileges, whatever the national interest may be. Past French governments have always caved in to them and abandoned reform. It remains to be seen whether Sarko has the stamina for a real fight.

Without serious reform, however, the situation in the banlieues can only get worse--and even with reform, it is not guaranteed to get better. In 2005, les jeunes did not venture beyond the confines of the banlieues because they knew the fearsome CRS, the riot police, were waiting for them if they did. However, if they, les jeunes, ever thought they could overwhelm the forces of order, they might not hold back in the same way: and then the real violence would begin, and would make 2005 seem like a garden party.

For a foreigner, the curious thing about France is that it is but a hair's breadth away from the greatest prosperity. One legacy from les trente glorieuses, the 30 post-war years when France experienced rapid economic growth despite several humiliations abroad, is an excellent infrastructure. France's population appears notably more intelligent and better educated than, say, the British (which is not, of course, to say much). Its labor productivity is among the highest in the world. Many of its companies are the best run in Europe. France is the most visited country on earth, and more people want to visit it than anywhere else. There is no field of human endeavor in which the French have not excelled. These days, they even speak good English.

And yet nowhere is fear of the future greater than in France, or the feeling stronger or more prevalent that decline is inevitable and irreversible. Years of intellectual propaganda about the horrors of economic competition have sapped the faith of the French in their ability to compete without being pauperized. The very word "Anglo-Saxon" in French newspapers is shorthand for the kind of lawless Wild West society that they think reigns in Britain and, especially, the United States, where robber barons pay armed killers to wipe out the competition and thousands of people die daily on the streets from eminently treatable diseases. It is to this mindset that les acquis--collective privileges such as early retirement, endless sick pay, and subsidized vacations (all of which raise taxes to one of the highest levels in the Western world, and from the benefits of most of which the inhabitants of the banlieues are rigorously excluded)--seem so desirable and so worth fighting to preserve. If in the name of equality and social justice society is divided into castes with no mobility between them, then so be it.

Sarko has been called American in his attitudes, but has taken it as a compliment rather than as a criticism. His problem is that, without reform, France is headed for very serious violence, amounting almost to civil war; with reform, it is headed for serious, though temporary, conflict. But the reward of reform is that France would soon be one of the very richest countries in the world, as well as what it is now, the country with the highest per capita consumption of tranquillizers.

Mr. Dalrymple is a retired prison psychiatrist and a contributing editor of City Journal. He is the author, most recently, of Romancing Opiates: Pharmacological Lies and the Addiction Bureaucracy.