FOR many Jews, it was a weekend of double horror in Brussels. On May 24th a gunman entered the Jewish Museum in the Sablon and opened fire with a Kalashnikov, killing four people. The next day, the first results of the European elections flashed up on a giant screen showing that far-right parties, including avowed neo-Nazis, had scored big electoral victories.

To some, the events seemed connected: Europe was reverting to ugly old ideologies and the shooting was proof, if it were needed, that Europe is no longer safe for Jews. Israeli leaders said the killings were the result of “constant incitement” against the Jewish state. An American journalist, Jeffrey Goldberg, caused a stir with a tweet: “At what point do the Jews of America and the Jews of Israel tell the Jews of Europe that it might be time to get out?”

To many European Jews, the idea is preposterous. Yet thoughts of leaving are not far below the surface. Returning to the Promised Land is at the heart of Jewish tradition and modern Zionism. A survey last year by the European Union’s Fundamental Rights Agency showed that nearly a third of Jews had considered leaving in the previous five years because they did not feel safe. Three-quarters felt that anti-Semitism was worsening, with the situation in Hungary and France especially bad.

For years there has been a particular worry about France, home both to Europe’s biggest Jewish community and to its largest Muslim minority. The controversy over performances by the comedian, Dieudonné, and his popularisation of the “quenelle” gesture (supposedly a modified Nazi salute) stokes belief in entrenched hatred of Jews. French criticism of the Israeli government, plus an EU-wide campaign for boycotts of products from Jewish settlements, has led some to argue that anti-Zionism is a hidden form of anti-Semitism. The success of the National Front, which came first in the European election, is a new cause for concern. It is part of a wider surge across Europe, including the election of neo-Nazis in Greece, Hungary and even Germany.

Israel’s Jewish Agency says there has been a fourfold increase in the number of French Jews emigrating to Israel in the first quarter of this year, compared with the same period last year. French is often heard in fashionable districts of Tel Aviv. How much of this flow is attributable to fear of anti-Semitism, and how much to the economic stagnation of France, is hard to judge; many French citizens, Jewish and non-Jewish, are abroad, not least in London.

The killing of children at a Jewish school in Toulouse in 2012 was horrifying. The attacker, Mohamed Merah, who died in a shoot-out with police, had much in common with Mehdi Nemmouche, the presumed attacker of the Jewish Museum in Brussels, who was arrested in Marseille during a customs check (he has denied the charge). Both were young men of north African extraction with a history of petty crime who seem to have been radicalised in jail and were in touch with jihadists abroad—the first in Afghanistan, the second in Syria.

For Europe’s intelligence agencies and security forces, the Brussels attack confirms their worst fears of the threat posed by young European Muslims who are fighting in Syria. Many will no doubt come home, some might continue to commit violent acts or even try to kill Jews. Synagogues and Jewish schools across Europe have received extra protection. Some people stay away from obvious Jewish targets. Hebrew-speakers consider switching language when talking in public. Even if Jews have not left Europe, argues Daniel Schwammenthal of the American Jewish Committee, some have “already emigrated from their communities”.

There was a time when the new Europe opening after the fall of the Berlin Wall seemed to augur a golden age for European Jewry. Jewish life was restored where it had been extinguished, and the expanding borders of a post-national Europe offered new opportunities to Jews scattered across borders. Plainly, nationalism is reasserting itself. And lingering anti-Semitism of the old, Christian-based sort is now mixed with radical Islamism among disenchanted Muslims.

Unpack your bags

Yet, worrying as such changes are, they may not be a signal for Jews to pack up and leave. To state the obvious, anti-Semitism in Europe is not sponsored by governments, and there are no organised pogroms or Nuremberg laws. Berlin boasts the world’s fastest-growing Jewish community. Jews are free to stay or leave. Moving to Israel may fulfil a religious, cultural or political need for many Jews, but it is not safer than staying in Europe.

Moreover, if new populist parties have done well, it is in part because many have worked hard to detoxify themselves. Where Jean-Marie Le Pen would talk of the gas chambers as “a detail” of history, his daughter, Marine, now calls the Holocaust “the height of barbarity”. The populists’ anger is directed much more against Muslims than against Jews.

If this is all an attempt to hide old-style anti-Semitism, the image-scrubbing has been helped by some Israeli and American Jewish groups. The likes of the Party for Freedom in the Netherlands have been welcomed by hardliners in Israel even as Jewish groups in their countries have at times sought to isolate them. And what of the jihadist killers? The threat is real, but it can strike gentiles as well as Jews—whether in Europe or America.

The European political model may be fraying, but it still tries to maintain open and tolerant societies. The EU, though in need of reform, seeks the same across the continent. Such ideals are worth defending, including the right to dissent and to criticise Israel. The protection of Jews is an important test of Europe’s democracy, as is the treatment of other law-abiding minorities, including Muslims. Should the spirit of tolerance ever disappear, Jews may not be the only ones to leave Europe.

Economist.com/blogs/charlemagne