Refugee families camped in central Budapest, Hungary, in 2015. The same location was nearly empty this month. Mauricio Lima for The New York Times; Akos Stiller for The New York Times

LAMPEDUSA, Italy — On the beaches of Greece, thousands of migrants landed every day. In the ports of Italy, thousands landed every week. Across the borders of Germany, Austria and Hungary, hundreds of thousands passed every month.

But that was in 2015.

Three years after the peak of Europe’s migration crisis, Greek beaches are comparatively calm. Since last August, the ports of Sicily have been fairly empty. And here on the remote island of Lampedusa — the southernmost point of Italy and once the front line of the crisis — the migrant detention center has been silent for long stretches. Visitors to the camp on Monday could hear only the sound of bird song.

“It’s the quietest it’s been since 2011,” said the island’s mayor, Salvatore Martello. “The number of arrivals has dramatically reduced.”

Arrivals to Italy, Greece and Spain by Sea Oct. 2015 221,454 200,000 150,000 100,000 May 2018 10,495 50,000 2014 2015 2016 2017 2018 Arrivals to Italy, Greece and Spain by Sea Oct. 2015 221,454 200,000 150,000 100,000 May 2018 10,495 50,000 2014 2015 2016 2017 2018 Arrivals to Italy, Greece and Spain by Sea Oct. 2015 221,454 200,000 150,000 100,000 50,000 May 2018 10,495 2014 2015 2016 2017 2018 By Sarah Almukhtar | Source: United Nations High Commissioner for Refugees

It is the paradox of Europe’s migration crisis: The actual number of arriving migrants is back to its pre-2015 level, even as the politics of migration continue to shake the Continent.

On Thursday, leaders of the European Union are gathering in Brussels for a fraught meeting on migration that could hasten the political demise of the German chancellor, Angela Merkel, and unravel the bloc’s efforts to form a coherent migration policy.

Unauthorized Crossings Into Europe 2016 2018 –52% POLAND Width of arrows represents the number of crossings. Eastern Land Route UKRAINE GERMANY HUNGARY FRANCE –90% AUSTRIA ROMANIA –99% Eastern Mediterranean Western Balkans TURKEY ITALY SPAIN +147% GREECE Western Mediterranean –41% Western African –67% Mediterranean Sea MOROCCO Central Mediterranean ALGERIA LIBYA EGYPT Unauthorized Crossings Into Europe Width of arrows represents the number of crossings. –52% 2016 Eastern Land Route 2018 –99% –90% Western Balkans Eastern Mediterranean +147% Western Mediterranean –41% Western African –67% Central Mediterranean Unauthorized Crossings Into Europe 2016 2018 BELARUS –52% POLAND Width of arrows represents the number of crossings. For example, there were almost 160,000 unauthorized crossings on the eastern Mediterranean route in 2016 compared with about 15,500 crossings on the same route in 2018. Eastern Land Route GERMANY UKRAINE HUNGARY AUSTRIA FRANCE ROMANIA –99% –90% Western Balkans Eastern Mediterranean SPAIN ITALY TURKEY +147% Western Mediterranean GREECE –41% TUNISIA –67% Western African Mediterranean Sea MOROCCO Central Mediterranean ALGERIA EGYPT LIBYA Unauthorized Crossings Into Europe 2016 2018 BELARUS –52% POLAND Width of arrows represents the number of crossings. For example, there were almost 160,000 unauthorized crossings on the eastern Mediterranean route in 2016 compared with about 15,500 crossings on the same route in 2018. Eastern Land Route GERMANY UKRAINE HUNGARY AUSTRIA FRANCE ROMANIA –99% –90% Western Balkans Eastern Mediterranean SPAIN ITALY TURKEY +147% Western Mediterranean GREECE –41% TUNISIA –67% Western African Mediterranean Sea MOROCCO Central Mediterranean ALGERIA EGYPT LIBYA Unauthorized Crossings Into Europe 2016 2018 BELARUS Width of arrows represents the number of crossings. For example, there were almost 160,000 unauthorized crossings on the eastern Mediterranean route in 2016 compared with about 15,500 crossings on the same route in 2018. –52% POLAND Eastern Land Route GERMANY UKRAINE HUNGARY AUSTRIA FRANCE ROMANIA –99% –90% Western Balkans Eastern Mediterranean SPAIN ITALY TURKEY +147% Western Mediterranean GREECE –41% TUNISIA –67% Western African Mediterranean Sea MOROCCO Central Mediterranean ALGERIA EGYPT LIBYA Unauthorized Crossings Into Europe BELARUS 2016 2018 POLAND –52% Width of arrows represents the number of crossings. Eastern Land Route GERMANY UKRAINE HUNGARY AUSTRIA FRANCE ROMANIA –99% –90% Western Balkans Eastern Mediterranean SPAIN ITALY TURKEY +147% Western Mediterranean GREECE –41% TUNISIA –67% Western African Mediterranean Sea MOROCCO Central Mediterranean ALGERIA EGYPT LIBYA By Sarah Almukhtar | Source: Frontex. Note: Unauthorized crossings show totals for each route from January to April of each year.

The precipitous drop in migrant arrivals doesn’t mean that Europe is without real challenges. Countries are still struggling to absorb the roughly 1.8 million sea arrivals since 2014. Public anxiety has risen in countries like Germany after high-profile assaults involving migrants, including the killing of a 19-year-old German student and the terrorist attack on a Christmas market that killed 12 people.

And leaders still have sharp disagreements about who should take responsibility for the newcomers — border states like Greece and Italy, where most migrants enter Europe; or wealthier countries like Germany, which many migrants subsequently attempt to reach.

But what is striking is how many leaders, particularly in far-right parties, continue to successfully create the impression that Europe is a continent under siege from migrants, even as the numbers paint a very different picture.

“We have failed to defend ourselves against the migrant invasion,” Viktor Orban, the far-right prime minister of Hungary, said in a recent speech. He has made it a jailable offense for Hungarians to assist undocumented migrants.

Nor is Mr. Orban alone in taking a hard line. Since the start of the month, Matteo Salvini, the Italian interior minister, has closed Italy’s ports to charity-run rescue boats. Horst Seehofer, the German interior minister, has threatened to turn back refugees at his country’s southern border. And across the Atlantic, President Trump has claimed, wrongly, that migration led to a crime epidemic in Germany.

The tactics seem to have worked. Data released this month by the European Union showed that Europeans are more concerned about immigration than about any other social challenge. Mr. Salvini’s party is now leading in Italian polls, up 10 percentage points since an election in March. Mr. Orban won re-election in April with an increased majority, after a campaign in which he focused almost exclusively on migration.

Even on Lampedusa, Mr. Martello won the mayoralty last year by promising to focus more on local issues than on burnishing the island’s international reputation as a place of sanctuary for migrants.

But the reality on the ground is that, despite the rhetoric, migration is back to pre-crisis levels — and has been for some time.

Lampedusa, Italy, in May 2017 and in 2018. Chris McGrath/Getty Images; Kyodo, via Associated Press

More than 850,000 asylum seekers arrived in Greece in 2015, with most of them eventually making their way to northern European countries like Germany. So far this year, little more than 13,000 have made the same journey. More than 150,000 people arrived in Italy in 2015; the number so far this year is less than 17,000. In 2016, when applications were at their highest, more than 62,000 people sought asylum in Germany, on average, every month. This year, that average has fallen to little more than 15,000 — the lowest since 2013.

On Lampedusa, more than 21,000 migrants landed in 2015. So far this year, the figure is less than 1,100. Only in Spain have arrival numbers risen, from more than 16,000 in all of 2015 to just over 17,000 so far in 2018. But the increase is still comparatively small — more people would arrive in a single week on the Greek island of Lesbos at the height of the crisis than are likely to arrive in Spain this year.

“It’s an invented crisis,” said Matteo Villa, a migration specialist at the Italian Institute for International Political Studies. “The high flows of the last years have bolstered nationalist parties, who are now creating a crisis of their own in order to score cheap political points.”

Mr. Salvini and Mr. Orban have cultivated popular support by creating the impression that they are the only leaders willing to make the tough decisions needed to reduce migration. Yet the European establishment, under pressure from the likes of Mr. Orban and Mr. Salvini, has been quietly working for some time with the main gatekeepers along the migration trails to Europe, including with authoritarian regimes, to bring the numbers down.

In Italy, arrival numbers plummeted after Mr. Salvini’s predecessor controversially persuaded several militias to halt the smuggling industry in northern Libya, and to keep thousands of would-be migrants in dangerous conditions in makeshift Libyan detention centers.

“The measures implemented by the previous government, which Salvini was so critical of, have actually been effective,” said Andrew Geddes, director of the Migration Policy Center at the European University Institute in Florence, Italy.

At the same time, several European governments have made deportation agreements with Sudan, whose leader, Omar Hassan al-Bashir, has been charged with war crimes charges. A deal with Niger has helped a crackdown on smuggling in the Western Sahara. And most controversially, the German and Dutch governments brokered a European Union deal in 2016 with the authoritarian government of Turkey that led to an immediate and drastic drop in migration to Greece.

Lesbos, Greece, in 2015, and in March 2018. Sergey Ponomarev for The New York Times; Mauricio Lima for The New York Times

“The paradox is that, in this narrative that Merkel opened the E.U.’s borders, it was in fact Merkel, with the Dutch, who negotiated the most effective agreement on the borders of the E.U.,” said Gerald Knaus, director of the European Stability Initiative, a Berlin-based research group that first proposed the deal, and that drafted early versions of it.

Now Europe’s challenge is largely about process: How to house asylum seekers waiting for decisions on their cases; how to integrate them into the economy and into society if their applications are approved; and how to deport them if not. These challenges remain as officials also have yet to fully address the squalid migrant camps of Greece, which house roughly half of the country’s 60,000 asylum seekers, or the underground economy of Italy, where many of the country’s 500,000 undocumented migrants are exploited.

The European Union summit meeting that opens on Thursday is a reminder of how much the political landscape has shifted. Ms. Merkel, the German chancellor who was once the Continent’s unassailable leader, now needs to secure an agreement with other European leaders to stave off a political crisis at home.

Her rebellious Bavarian interior minister, Mr. Seehofer, has threatened to close Germany’s border with Austria to asylum seekers who have already registered elsewhere in Europe, usually in Greece or Italy. Ms. Merkel wants to avoid this, as it would most likely set off a domino effect of stricter border controls across the Continent. That would obstruct the movement not just of refugees but also of European Union citizens, endangering one of the bloc’s core values: free movement between member states.

Mr. Seehofer has agreed to wait while Ms. Merkel tries to negotiate at the summit meeting an improved asylum system for the European Union, but this seems a distant prospect, as no one can agree what that system should look like. Some leaders, like Mr. Orban in Hungary, say that Europe should simply protect its borders without worrying about the complexities of its asylum system.

The Keleti train station in central Budapest, Hungary, in 2015 and this month. Mauricio Lima for The New York Times; Akos Stiller for The New York Times

“If we defend our borders, the debate on the distribution of migrants becomes meaningless, as they won’t be able to enter,” he said in a speech this month.

Others, like Ms. Merkel, want to reduce migration but acknowledge it cannot be ended entirely unless Europe abandons the right to asylum that was enshrined in the international conventions that emerged in the aftermath of World War II.

To uphold this right while also curbing migration, officials in Brussels want to set up offshore hubs to process asylum applications in Africa, while some analysts argue it would be easier and cheaper to invest in more efficient asylum systems in Greece and Italy — and to secure more deportation agreements with the countries migrants are originally from.

Meanwhile, anti-immigrant leaders, if capitalizing on the migration issue, are hardly unified. Italy wants to scrap the Dublin regulations, which stipulate that asylum seekers must stay in the European Union country in which they first register, and distribute migrants throughout the bloc. But hard-liners like Mr. Orban, Mr. Seehofer and Chancellor Sebastian Kurz of Austria refuse to share Italy and Greece’s burden.

“Their proposals are fundamentally contradictory,” Mr. Knaus said. “Salvini and the Italians want to get rid of Dublin and share everyone throughout Europe. The Bavarians want to push everyone back to Austria. And Kurz says that’s fine — we’ll then send them to Italy and Hungary.”

And far away on Lampedusa, this makes the debate seem less about the specifics of migration management, and more about the widening chasm between liberal and illiberal forces in Europe.