Preventing the Next Jewish Exodus

History has shown that where Jews can’t live safely, everyone is at risk.

In an interview conducted before the recent Paris massacres at Charlie Hebdo and the Hyper Cacher kosher supermarket, French Prime Minister Manuel Valls warned that “if 100,000 Jews leave, France will no longer be France. The French Republic will be judged a failure.”

For this to be avoided, we must concentrate less on the result—a mass Jewish exodus—and far more on the means of prevention. European Jews who survived millennia of discrimination, persecution, the Inquisition and the Holocaust are growing increasingly insecure. But the question of how to fight for survival isn’t one that should be posed to law-abiding citizens of a Western democracy. It is for their governments and authorities to keep Jewish communities secure and allow them to live in normalcy. Not just in France, but across Europe, Jews have resorted to building severe fortifications around their communal institutions to allow the activity inside to continue as normal. No one who has ever seen a Jewish kindergarten with high concrete walls covered with barbed wire and guarded by armed security guards can be anything but deeply disturbed by the sight. The Jewish community shouldn’t be asked to retreat into a ghostlike existence like this. We are told not to wear identifying signs, to remove or hide distinguishable features from buildings, and to keep solely to certain areas. All this so we don’t become targets of anti-Semitic attacks like the many Jews who have been murdered or wounded in recent years on the streets of Europe.

The decision by the French authorities to close down the Jewish area of the Marais district after the massacre at the Hyper Cacher supermarket is a symptom of this problem. While it is understandable that the authorities chose to take measures to prevent further loss of life, the fight must be taken to the perpetrators rather than allowing it to infringe further upon the everyday lives of the victims. The recent attacks on Charlie Hebdo and the kosher supermarket call for a serious rethink of strategy, not just to protect Jewish communities but our very society, which is increasingly under threat.

In the immediate term, intelligence-gathering and -sharing across Europe must increase. The current system is neither efficient nor vigilant enough. As one example, Mehdi Nemmouche, who is currently on trial for the massacre at the Jewish Museum in Brussels last year, fled through three countries before finally being caught, even though he was already on a watch-list, a convicted felon known to have been involved in crimes in Syria. It is now also known that all of the perpetrators of last week’s attacks in Paris were on the radars of intelligence and police officials. The question of prevention must be readdressed, because the current paradigm is simply not working.

Police and law enforcement also need to be strengthened. This includes actively enforcing laws against incitement and anti-Semitic speech, taking a firmer approach against those who promote hate and violence. Authorities also need to create laws that deal not only with the general commitment to tolerance, but define the values that need preserving and the limitations of tolerance toward those who risk the security of their fellow citizens and their society.

In the longer term, education is vital. We must break the cycle of radicalism that allows for children in some communities to justify these murders, as many children have reportedly been doing in some Muslim-majority schools since the massacres. We must give these children a better future, free from the radicalization and incitement that has increased largely unchecked for far too long. Our school curricula need to impart the necessity of tolerance for others. We need to teach our children, from a young age, that it is acceptable to disagree with someone but that it must be done in a respectful manner. This would allow children to channel their thoughts in a positive, rather than a reactionary, manner.

To win this war—and it is a war, as Prime Minister Valls has so courageously defined it—we must take it to the perpetrators and not let them win by imposing further measures on the victims, because this will lead to the results they seek.

The pressure on Jewish communities across the Continent is at a breaking point and, as a result of the almost daily attacks and threats, some cities are already almost Jew-free. The future of European Jewry is thus a test for Europe. If the authorities and society succeed in protecting its Jewish communities, then Europe will prevail. Because history teaches that Jews’ feeling of security is a good barometer of the health of a society. Where Jews can’t live safely, everyone is at risk. From that perspective, recent events indicate that Europe is under grave threat.

Mr. Kantor is president of the European Jewish Congress.