WARSAW, Poland — With hundreds of thousands of migrants pouring across its borders, and economic and political pressure growing to enact tighter controls, Europe has nevertheless stayed fairly steady in its response to the humanitarian emergency.
But after the attacks Friday in Paris, fears that Islamic terrorists might infiltrate the migrant flow have deepened across the continent, and the talk has shifted sharply to security over compassion.
Officials across Europe were calling for even stronger border controls, stricter screening of those arriving and some way to persuade people to stay in the Middle East.
So far, it is mostly talk. But in recent weeks, European countries from Sweden to Slovenia have been enacting new border controls, erecting border fences and discussing ways to better screen and register the migrants.
And since the attacks by militants, and the discovery of a passport of a recent Syrian migrant near the scene of a suicide bombing, the rising anti-migrant sentiment seems poised to substantially shift the conversation. Perhaps it could even change both policies and attitudes toward the migrants, as they arrive, make their way across Europe and land in the countries where they hope to make their homes.
In the short run, this shift in tone could complicate the only significant plan the European Union now has to slow down or bring order to the resettling of more than 1 million people: its plans to relocate 160,000 migrants across Europe. It also could affect future attempts by the bloc and others to fashion a more comprehensive and unified approach to the crisis.
Germany, which has accepted the largest number of migrants and is the destination of choice for many of them, is crucial to any solution to the crisis. But even there resistance is growing.
"The days of uncontrolled immigration and illegal entry can't continue just like that," Markus Soder, Bavaria's finance minister and a leader of its Christian Social Union, insisted in an interview Sunday with the Welt am Sonntag newspaper. "Paris changes everything."
Much of the harshest language is coming from Eastern European leaders, who have never been warm to the arrival of thousands of largely poor and Muslim migrants. Since the attacks in Paris on Friday, leaders have stepped up their criticism.
Karl Erjavec, Slovenia's foreign minister, warned the Paris attacks made it clear that hiding among the throngs of migrants are some "with bad intentions."
"This atrocious act confirms that we are entering difficult times," said Milos Zeman, president of the Czech Republic. "We cannot fight international terror with protests and demonstrations anymore."
Andrej Babis, the Czech finance minister, said Europe was at war and concrete steps needed to be taken.
The concerns were not limited to government officials.
"Along with refugees, there are also terrorists coming," Mariana Koleva, 40, said on a shopping trip to Edirne, Turkey, from her home in Bulgaria.
"I don't want Romania now to receive migrants, especially after what happened in Paris," said Gabriela, 38, a bank analyst in Bucharest who declined to give her last name because her employer would not approve. "We could also be in danger in the future."
Marie Hermanova, the spokeswoman for a team of Czech volunteers who have been working with the migrants, said her group was bracing for a rising anti-migrant mood.
"What happened in Paris on Friday night is happening in Syria every day, and it is exactly why those people are running away," she said. "Our volunteers are extremely unhappy about the wave of hate this will likely release."