While Prime Minister Netanyahu is pressing the attack in Gaza, he may want to get ready to send in Israeli paratroopers to protect the Jews of France. That may sound rash. But to judge by the events in Paris this week, the government of President Hollande doesn’t seem to be up to the job. No sooner did Israel move to protect its population from the rocketing out of Gaza than an anti-Semitic mob splintered off from a protest and descended on a Paris synagogue — with 200 worshippers inside.

According to a witness quoted by the Jewish Telegraphic Agency, the mob had “murder on its mind.” The police guard at the venerable Don Isaac Abravanel Synagogue was inadequate. Only Jewish community self-defense groups averted a ghastly tragedy. Things have only escalated since then, with ever more violent protests ostensibly over Gaza. “Ostensibly” because anti-Semitism is never about Jewish behavior. What’s happening in France is a deeper, abiding hostility than Gaza.

After all, the congregation of the synagogue in the rue de la Roquette did nothing to the Gazans. No, the Paris mobs are out for the blood of French Jews. On Sunday they attacked the part of a suburb of Sarcelles that is known as “Little Jerusalem,” setting Jewish establishments on fire and burning cars. These attacks are occurring 10 years almost to the day since Prime Minister Sharon, in a memorable demarche, called for the evacuation of all the Jews of France.

Sharon had noted that all of his country’s prime ministers seek to encourage Jews to move to Israel. “I say that to all Jews around the world,” Mr. Sharon said. In the case of France, Sharon warned, “I think it’s a must and they have to move immediately.” Sharon’s statement was in July 2004. It caused the Quai D’Orsay to erupt in the kind of indignation the French have raised to a high art, but Sharon never withdrew his warning.

Sharon had issued his call after, in the space of a few weeks, vandals destroyed a mural painted by Jewish schoolchildren, a 17-year-old Jewish student was stabbed in the neck, a town hall in Vichy was painted in swastikas, “Jews out” was painted on graves at Colmar, a Jewish center was set on fire at Toulon, and a school for Jewish boys was firebombed.

For all the sputtering at the time from the Quai D’Orsay, France did nothing to attenuate its support for the Palestinians. And that is important. In 2001, a French ambassador in London told a dinner party, “All the current troubles in the world are because of that sh**ty little country Israel.” The ambassador, Daniel Barnard, got reassigned but was defended by the foreign ministry and the Paris press. He had said what the French elite think.

France’s leaders are this week insisting otherwise, that they are against anti-Semitism. Prime Minister Valls on Sunday put out a statement, condemning, according to the Jerusalem Post’s cable, the “anti-Semite who hides his hatred of the Jew behind an appearance of anti-Zionism and the hatred of Israel.” This is why more and more Jews are leaving France, a trend that has been covered by our erstwhile contributor, Michel Gurfinkiel. Violence against Jews would not be permitted, Monsieur Valls averred. On verra, as the French say. Our own instinct is that it would be wise for Mr. Netanyahu to make contingency plans.