WASHINGTON—The problem is not Nicolas Sarkozy, France’s president-elect. The problem is the country that elected him. Sarkozy knows what needs to be done to rescue France from the socialist illusion in which it has been living for far too long under governments both of the left and the right. But the question is: Are the French prepared to do what it takes to reverse their country’s decline or will they turn a Sarkozy presidency into another lost opportunity?

Matthew Parris, one of Britain’s finest commentators, thinks France is simply not ready for Sarkozy. In a recent article in the Times of London, Parris wrote that for all their impatience with economic stagnation, unemployment, social ghettos burning in the suburbs and the proliferation of violent youth groups, the French are not ready to make the “emotional leap” necessary to reform a system under which people are used to relying on the government rather than on their own efforts for their welfare.

“I don’t sniff in the wind in la France profonde (though I begin to in urban Paris) that palpable sense of having reached the end of a road,” Parris wrote. “The changes France needs to embrace will be convulsive. The pain will be intense.... We British found that when Thatcherism arrived. But even at the low point of Thatcher’s first term ... you almost never heard anyone suggest a return to what had gone before. There was a sense, in 1979, that we had burnt a bridge behind us, and had wanted to.”

Why should it matter to the rest of the world whether France is ready to change course? Because the European Union will not achieve political maturity until France reverses its decline. In one generation, that country has gone from being one of the eight wealthiest in the world to 17th; its public debt has quintupled since 1980. Sure, many European countries have modernized their institutions without waiting for France, but France, together with Germany, has kept the European Union from playing the international role it was destined to play. The result has been a disproportionate role—politically and economically—of the United States among the free nations of the West, something that is beginning to show now that America seems to be slowing down.

In today’s France, Sarkozy is a more promising leader than anyone else on the right or on the left. His flaws notwithstanding—he betrays populist temptations from time to time—this son of a Hungarian immigrant is young enough and cosmopolitan enough to understand that France needs to put an end to the mentality that has governed it in recent decades. That mentality is essentially made up of two things: Gaullist nationalism of the kind that Valery Giscard d’Estaing and Jacques Chirac, Sarkozy’s predecessors on the center right, felt too comfortable with, and the kind of socialism that turned the student revolt of May 1968 from an explosion of libertarian sentiment into a conformist dependency on big government as the solution to most social ills.

Has his election come too early, as Parris thinks? I don’t know, but the odds favor his pessimism.

It is difficult to anticipate a country’s readiness for change because so much depends on the leader’s capacity to transform the prevailing mentality and on whether the initial results generate a critical mass of support for additional reform. In 1970, Ted Heath, then Britain’s new conservative prime minister, tried reform but failed. Nine years later, Thatcher tried more forcefully and succeeded. In 1995, France’s Chirac promised to shake France out of its complacency with a few timid reforms. But he quickly reversed course because his country was not ready. He tried again 11 years later through his prime minister, Dominique de Villepin, and failed again.

It is hard to tell how many of Sarkozy’s voters—53 percent of the electorate in the second round—cast ballots for structural reform and how many simply favored law and order, or opposed the kind of permissiveness that they tend to associate with socialism. I suspect that the second group far exceeds the first.

What that second group doesn’t yet know is that in today’s France, structural change is the condition for law and order. What has caused the moral decline conservative voters so fear is precisely the suffocating system that, with the exception of a few corporate success stories at the top, keeps most French working too little and complaining too much.