Increasing worries over terrorists sneaking into EU nations in the garb of Syrian refugees have already seen Poland declare it won't accept Middle East refugees despite agreeing to the EU's quota plan for distribution of refugees. And more EU members are likely to set stricter rules for accepting refugees, or even other immigrants.

The Paris attacks also have exposed the failure of the multicultural policy in Europe, because many Muslim immigrants are still unable to join the EU mainstream. Even though the second-and third-generation immigrants are eager to be part of the European mainstream, many cannot because of differences in language, values and cultures. The education such Muslim immigrants and their children often get is below par and so many of them remain unemployed and are pushed to the margins of society.

Islamic extremism appeals to some of them because it gives them a sense of belonging. And the Paris attacks could further widen the gap between Muslim immigrant communities and mainstream European society, and thus worsen the situation in Europe.

Still, one cannot say the attacks will force EU countries to reverse their relatively loose immigration policies. Many EU countries have loose immigration policies because of their low birth rate, aging populations and declining workforce. So, as long as terrorist attacks don't take place frequently, they are unlikely to reverse their immigrant policies.

After the attacks, European Commission President Jean-Claude Juncker said there is no need for a complete rethink on the refugee policy but emphasized the importance of the EU plugging the loopholes that threaten border security. "Those behind the attacks in Paris cannot be put on equal footing with refugees who are seeking asylum," he asserted.

European Council President Donald Tusk, on his part, emphasized the necessity of strengthening coordination among EU nations to more effectively supervise the funds that could be flowing through their financial systems into terrorists' hands in order to cut off all fund-supply routes to terrorist outfits.

Therefore, the latest Paris attacks will cast a shadow on EU countries' immigration policies but not lead to a fundamental change. After all, Europe has prospered because of its openness and the EU's fight against terrorism can intensify without shutting the door on refugees and other immigrants.

The author is an associate professor at the School of International Studies, Nanjing University.