As Europe reels from the deadly attacks in Paris, the violence is deepening divisions on how to handle the region's refugee crisis and raising fears of an anti-foreigner backlash.
For months, an unofficial humanitarian corridor has allowed hundreds of thousands of people to pass from Greece through several Balkan nations and on to Western Europe. The new arrivals – from Syria, Afghanistan, Iraq and elsewhere – have provoked both sympathy and alarm. European Union leaders are bitterly split on how to respond to the influx, which is a direct test to the system of open borders within much of the bloc.
Now it appears that at least one of the attackers in Paris may have posed as a refugee to enter Europe. Such a tactic would confirm a risk long cited by security experts – that among the multitudes crossing the Mediterranean this year, there could be some who are seeking neither safety nor a better life, but rather to inflict harm.
The potential link between one of the attackers and the movement of refugees will make it even harder for European leaders to forge a unified response to the migration crisis. It's also likely to strengthen the hand of the region's far-right parties, which have warned of possible dangers associated with the influx. An early test arrives next month with regional elections in France, where the right-wing Front National is expected to make gains at the ballot box.
On Sunday, a senior European leader urged calm and admonished politicians not to conflate refugees with violent extremists. Those who "perpetrated these attacks are exactly the ones whom the refugees are fleeing," said Jean-Claude Juncker, president of the European Commission, in a reference to Islamic State militants. "As a result, there is no reason to reconsider in broad terms Europe's policy toward refugees."
Mr. Juncker repeated that he wanted to be "crystal clear that we should not mix the different categories of people coming to Europe." Then he delivered a direct message to European politicians linking refugees to terrorism: "I would like to invite them to be serious about this and not to give in to these basic reactions."
Much remains unknown about the attacker who may have posed as a refugee. A Syrian passport was discovered near to one of the attackers who targeted a Paris stadium on Friday night. On October 3, a man carrying the same passport passed through the Greek island of Leros, one of the starting points for those making the journey from Turkey toward Western Europe. Four days later, he crossed into Serbia from Macedonia.
However, it's unclear whether the passport actually belonged to the attacker or to someone else. Some experts have also cautioned that the passport could be a forgery: fake Syrian documents are available for sale in Turkey for those seeking to bolster their claim to refugee status.
In Poland, the newly elected conservative government didn't see the need to await further details. The country's future minister for European affairs, who will take office this week, said Poland could no longer fulfill its prior commitment to take in 9,000 asylum seekers – part of a mandatory burden-sharing deal among EU nations.
"In the wake of the tragic events in Paris, Poland doesn't see the political possibilities to implement a decision on the relocation of refugees," said the incoming minister, Konrad Szymanski, according to Bloomberg News. Poland must have full control over its borders, he said, and demanded "security guarantees" before taking in asylum seekers.
In Germany, the Paris attacks have unleashed a new torrent of criticism toward Chancellor Angela Merkel's policies. Ms. Merkel has been the strongest voice in Europe for opening the door to those fleeing war and conflict and who deserve protection under international law.
"The days of uncontrolled immigration and illegal entry can't continue just like that," said Markus Soeder, a minister in the state of Bavaria, Reuters reported. "Paris changes everything."
Mr. Soeder belongs to the conservative Christian Social Union, a party that is allied with Ms. Merkel's Christian Democratic Union but highly critical of it on the refugee issue. Ms. Merkel should acknowledge that opening the border "for an unlimited period of time was a mistake," Mr. Soeder said.
Right-wing parties across the continent – wary of immigration even under normal circumstances – are likely to seize on any link between the Paris attacks and migrants to bolster public support. In France, Marine Le Pen, the leader of the Front National, said on Saturday that "it is absolutely necessary that France regains control of its borders." France must "ban Islamist organizations, close radical mosques and expel foreigners who preach hatred in our country as well as illegal migrants who have nothing to do here," she said.