The last time Islamic terrorists attacked Paris, they brought Europeans closer together.
Following the Charlie Hebdo murders in January, citizens from across the continent took to social media to show solidarity using the hashtag #JeSuisCharlie. European leaders walked arm-in-arm in Paris in defense of European values and free speech. Governments promised to work even more closely together to combat terrorism and religious extremism.
The latest attacks on Paris have engendered similar displays of sympathy, but they do so against an altogether more contested political landscape.
The arrival of more than a million refugees in the European Union this year has fueled tensions both within and between countries. Razor wire fences once again run along some borders between EU members; several governments have reintroduced border checks; trust in the willingness and capacity of countries to enforce EU rules has been severely eroded; and the principle of free movement of people within the EU—a cornerstone of integration—has been widely called into question.
Only the day before the Paris attacks, European Council President Donald Tusk warned that the survival of the EU’s Schengen passport-free travel zone was at stake.
The fact that one of the Paris terrorists appears to have entered Greece alongside refugees in October—and evidence of a possible Belgian link to the plot—is bound to further erode public confidence in open borders. It may also boost support for right-wing populist politicians who insist that the answer to the terrorist threat and migration crises lies in national—rather than European—solutions.
Yet there is little sign so far that any national government is tempted by this populist agenda. Even the new right-wing Polish government, which initially responded to the Paris attacks by saying it would no longer participate in the EU’s refugee resettlement program, backtracked somewhat from its position on Sunday.
Instead, the attacks seem more likely to underline the central message behind Mr. Tusk’s warning: that unless EU governments swiftly take the necessary steps to restore trust in the security of the EU’s external borders, the wider benefits of European integration, including its single market, risk being lost.