LONDON — There was palpable relief in mainstream Europe on Monday at the success of the independent centrist Emmanuel Macron in the first round of the French presidential elections, and a wide assumption that he will defeat the far-right Marine Le Pen in a runoff two weeks from now.

After other recent electoral setbacks for far-right populists, and the far right’s flagging momentum in Germany’s election campaign, some even suggested that the French election could represent the high-water mark of the populist surge that has voted Britain out of the European Union and Donald J. Trump into power in the United States.

If this is a high-water mark, though, the water remains quite high.

For the moment, the parties and personalities that have energized far-right populism have not fully crystallized electorally. But the issues that have animated the movements — slow economies, a lack of jobs, immigration — are not going anywhere, and the far right has already moved the political terrain in its direction.

The politics of Europe remain, at best, precarious, even if the center — the French-German core of the European Union — appears to be holding, at least for now.

“There is a sigh of relief,” said Jan Techau, the director of the Holbrooke Forum at the American Academy in Berlin. “It’s good that in addition to all the other issues on the agenda, we don’t also have an extremist French problem.”

After a year of unpredictable elections in Europe and the United States, it would be unwise to discount Ms. Le Pen entirely, even if her odds are long. Still, the French result was particularly welcomed by Brussels and Berlin, which have been praying for a French partner willing to challenge both the statist structure of France and the complacency of the European Union. And after weeks of market jitters, investors on Monday cheered the results, with global stocks surging and the euro reaching fresh highs.

Mr. Macron believes in economic liberalism, a reformed France and a more flexible European Union, while Ms. Le Pen threatens to take France out of the bloc, which would in effect mean breaking it over her knee.

Jean-Claude Juncker, the president of the European Commission, broke protocol to congratulate Mr. Macron and wish him continued success, as did the German foreign minister, Sigmar Gabriel, who said, “He will be a great president.”

By winning more votes than Ms. Le Pen, Mr. Macron, who at 39 is on course to be France’s youngest head of state since Napoleon, seemed to many to be a new generation’s centrist answer to sclerotic and corrupt establishment politics and the challenge of populism and the far right.

Even so, candidates of the far right and far left did very well in the voting, reflecting strong and skeptical views among the French public.

“Of course many people in Brussels and so on are relieved that we don’t have two extremists in the last round, but only one,” said Guntram B. Wolff, a German who directs Bruegel, a Brussels-based research organization.

“But the fact of the matter is that we still have a little bit more than 40 percent of the electorate having voted for an extremist,” Mr. Wolff said. “So that shows that a large part of the French population doesn’t seem to be very happy with his or her own position and pretty dissatisfied with the political system.”

The question for many is whether a centrist reformer like Mr. Macron, a former investment banker, is prepared to seriously take on board the dissatisfaction of ordinary working people.

“That the flow of support towards the far-right populists has stagnated is a hopeful sign for European democracy,” Ska Keller and Philippe Lamberts,
the co-leaders of the Greens in the European Parliament, said cautiously in a joint statement.

“But the threat from the far right is not over,” they were quick to add. “If Macron is to take it on and defeat it, he needs to get real on social justice and do more for those who feel marginalized.”

Still, for a majority in Europe, the far right has not provided answers either, as it has fallen short of predicted triumphs.

In December, the far right was defeated narrowly in Austria’s presidential election. In a parliamentary vote in the Netherlands in March, the nationalist Geert Wilders failed to come first as predicted, though he did finish second. In Britain, the U.K. Independence Party, or UKIP, which pushed for the country to exit the European Union, has lost its only member in the national Parliament and is floundering before the June 8 elections.

Perhaps most significant, with crucial German elections this September, the populist Alternative for Germany, which rode a wave of anti-Islam, anti-migrant sentiment to seats in 11 of the country’s 16 state legislatures, seems to be running out of steam, mired in internal disputes.

Yet on traditional measures, Ms. Le Pen did very well in the first-round vote on Sunday. She received nearly 7.7 million votes, compared with her 6.4 million in the first round in 2012 and the 4.8 million that her father, Jean-Marie, received when he advanced to the second round in 2002.

While Ms. Le Pen is expected to lose in the runoff, Mr. Macron — as a youthful banker with an elite education — is an easy target for her. French unhappiness with establishment parties is sure to be reflected in the June votes for the French legislature, in which Mr. Macron and his year-old movement, En Marche!, will have to work hard to cobble together a working majority.

Robin Niblett, the director of Chatham House, a research institute in London, cautioned that populist views have been growing for many years, not just in southern Europe but in “more settled northern Europe,” like Sweden, Finland and the Netherlands.

“In a time of economic turbulence, there’s been a search for national identity and individual identity, a feeling that national identities are being stripped away at a pace people can’t control,” he said. “The E.U. is seen as an expression of that loss, and even a vehicle for it.”

As important, the far right’s nationalism and opposition to multilateralism have split mainstream parties and pushed the national conversation to the right.

“At the moment, conservatives are doing a better job at coalescing support and co-opting aspects of the populist message,” Mr. Niblett said. Each country has its own specific political context, he said, “but I don’t see the validity of the populist message declining.”

Giles Merritt and Shada Islam of Friends of Europe, a research institution in Brussels, hailed Mr. Macron, saying that if elected, he “would not only breathe new life into the Franco-German ‘locomotive’ but offer a more hopeful and upbeat message for the future.”

Germany especially is looking forward to a more like-minded French partner, as together they make up about 47 percent of the eurozone’s gross domestic product, said Daniela Schwarzer, the director of the German Council on Foreign Relations in Berlin.

“Macron understands Europe and the need to change things, and that means changing France, too,” she said, noting a speech by Mr. Macron in Berlin that directly linked “reform and modernization in France with reform in the E.U.”

That is the perfect line for Germany, she said, “which fears pressure for more burden-sharing with countries who haven’t done their economic homework.”

Mr. Macron has said he wants a common eurozone budget under a eurozone “finance minister” and has proposed “democratic conventions” to identify reform priorities for the European Union.

The Germans fear that if the eurozone integrates further with a budget and banking union, but without prior economic changes from its members, Germany will end up bailing out everyone else forever. So Mr. Macron, vowing economic reform in France, is singing a song much more attuned to German ears.

But Mr. Macron, if elected, is also expected to push a harder negotiating line with Britain over its exit from the European Union — especially on the issue of financial services, about which he knows a great deal.

“With his background, we assume Macron sees much more clearly where the actual issues lie and will work to prevent Europe from facing a competitive disadvantage,” Ms. Schwarzer said.

But there is much to play for, not just in Britain’s election in June but especially in Germany’s in September. Chancellor Angela Merkel faces a strong challenge from the center-left Social Democrats, and the far-right Alternative for Germany is likely to win seats in the federal Parliament for the first time.

At the far right’s party conference this past weekend in Cologne, there were strong themes of nationalism and distaste for immigration despite the party’s internal disputes, in which Frauke Petry, one of its leaders, lost her effort to pull the party away from the hard right.

Her rivals brought delegates to their feet with speeches that pandered to identity loss. Whether or not the party succeeds, the issue seems likely to
continue to resonate broadly.

Jörg Meuthen, a professor who leads the party with Ms. Petry, said that few Germans could be seen as one walked around a typical German town.
“This is our country,” he told cheering delegates. “The country of our grandparents and parents. We must take it back.”