Remember the words of the chorus of the Marseillaise, the national anthem of France? No? Let me remind you: “To arms citizens! Form your battalions! March on! March on! May impure blood water our fields!”

Well, this time the “impure” blood won the day. Nicolas Sarkozy was able to defeat Ségolène Royal — in the teeth of prejudice and despite his prominence in the hated ancien regime of Jacques Chirac.

How did he do it? When Mr. Sarkozy promised a revolution, he looked as if he meant it. Sarko, the man of the Right, was a more credible revolutionary than Ségo, the woman of the Left. The revolutionary card trumped all the others — including the anti-Semitic card.

“What France needs is a revolution.” Every Frenchman I have talked to during the recent election campaign said something like this. The women are in an even more revolutionary mood than the men, which is why a majority of them turned down the opportunity to elect their first female president.

During the 231 years of the American republic, France has had two empires, three monarchies, and five republics — not counting various occupations, the Paris Commune, and the Vichy regime. The present fifth republic has lasted longer than any of the others, but it has come close to collapse several times since 1968. Many people feel that only a new republic now can save France.

As much as the French love their revolutions, however, nowhere else is a revolution so likely to turn on its leaders as in France. Take just one example — Napoleon’s Hundred Days. Remember how the deposed emperor merely had to return from Elba, virtually alone, for the restored Bourbons to flee their throne without a shot being fired? Yet all those who cheered “Vive l’empereur!” deserted him after Waterloo. No nation is as eager to hymn its revolutionaries one day and guillotine them the next.

Even so, few would have predicted that Mr. Sarkozy’s honeymoon as president-elect would last less than 48 hours. On Sunday night alone, more than 1,000 cars were burned across France — and that is a gross underestimate. The riots have continued since. By yesterday, the mutterings of a nascent reaction could be heard: “Paris is burning — and where is Sarko? Sunning himself on a billionaire’s yacht in the Mediterranean! He’s just like all the others.”

Nobody knows whether Mr. Sarkozy will be true to his instincts, but they seem to be remarkably sensible. A pro-American president with a penchant for horseback riding is unlikely to sneer President Bush as a “cowboy” — as so many of his countrymen do.

France is a country where family still matters. A man whose maternal grandfather, Aron Mallah, was a Greek Jew, and who lost members of his family in the Holocaust, is unlikely to turn a blind eye to anti-Semitism. Mr. Sarkozy’s forebears on his mother’s side included two eminent Greek Zionists, so we may assume he means it when he says that Israel’s security is non-negotiable.

He is not hostile to immigrants who want to work — his father was a Hungarian refugee — but he wants to abolish employment laws that make it so hard to fire someone that nobody wants to hire anyone. And to risk the enduring hatred of the bien pensants by denouncing Muslim rioters as la racaille — “scum” — took courage.

There is, however, a contradiction here. Mr. Sarkozy presents himself as a revolutionary, but he actually represents the downtrodden bourgeoisie. His program is really one not of revolution but of restoration — a restoration of order in the streets, a restoration of economic freedom, a restoration of integrity in public life, and a restoration of France’s reputation abroad as a champion of liberty.

Whether we speak of the Sarkozy revolution or Sarkozy restoration, there are two factors that may defeat it. If the new president knows his French history, neither will be unfamiliar.

The first is the pathological polarization of French politics. The Anglosphere imported the terminology of Left and Right from France relatively late in the day. It was irrelevant to the unideological nature of British or American party politics in the 19th century, and it still feels alien now.

But in France, where parties are ephemeral but ideologies are eternal, Left and Right denote tribal loyalties. Countless French people have killed or been killed for no better reason than allegiance to the Left or the Right. This murderous propensity still exists. Mr. Sarkozy must never forget that his own side, the Right, has almost as ignominious a record as the Left. He surely remembers the French Left’s support for Stalin and Mao. But does he remember Valery Giscard’s support for Khomeini and Bokassa, or Mr. Chirac’s for Saddam and Arafat?

The second danger was first identified by Alexis de Tocqueville in his classic, L’Ancien Régime et la Révolution: “The most dangerous moment for a bad government is generally that in which it sets about reform.” If he is not resolute, if he flinches in the face of barbarism, not only will Mr. Sarkozy fail, he may bring down the republic that he is trying to save. In that case, he would be the first victim. French revolutions really do water the fields with blood.