A recent antisemitic incident in the French city of Marseille has spiralled into a cause celebre that amplifies the crisis afflicting Jews and Islam in France today.

On January 11, a machete-wielding 15-year-old Muslim Turkish boy slashed Benjamin Amsellem, a Jewish teacher, as he was taking a walk. The assailant told police he had acted in the name of Islamic State, the Sunni jihadist organization which aims to establish a caliphate in the Middle East, subjugate religious minorities and destroy the state of Israel.

Amsellem was attacked because he was wearing a skullcap. Shortly afterward, Zvi Ammar, the president of Marseille’s sizeable Jewish community, warned his fellow Jews to refrain from donning yarmulkes in public. “Remove the kippa during this troubled time until better days,” he declared in a comment that set off an anguished nation-wide debate.

Some Jews agreed with his recommendation. Still others didn’t. The chief rabbi of France, Haim Korsia, opposed the idea. “It means we are projecting part of the responsibility on the victim,” he said. “We must not cede to emotion.”

He had a point.

Horrified by the obnoxious notion that Jews should conceal their identity, French President Francois Hollande courageously jumped into the fray. “It is intolerable that in our country citizens should feel so upset and under assault because of their religious choice that they would conclude conclude that they have to hide,” he said.

Hollande delivered his cri de coeur at a moment when the Jewish community in France, Europe’s largest and the first to be emancipated, has never felt as threatened or as vulnerable since the Vichy era, during which 75,000 Jews perished.

Coincidentally, Hollande’s poignant comment meshed with a somber anniversary. A year ago this month, three French-born Arab Muslim jihadists killed 17 people in two separate terrorist attacks in Paris directed at the Charlie Hebdo satirical weekly and a kosher supermarket in the eastern part of the city.

These attacks were followed by a series of murderous assaults in Paris last November during which 130 people were killed. Once again, the perpetrators were Muslims, some of whom held Belgian citizenship but all of whom were aligned with Islamic State.

As a result of these deadly rampages in France, and earlier attacks that unfolded in Denmark and Belgium, Jewish emigration from Europe has risen significantly. According to figures released by the Jewish Agency in Jerusalem, nearly 10,000 Western European Jews immigrated to Israel in 2015, a record number.

Of these new immigrants, almost 8,000 were French Jews, who obviously feel frightened, intimidated and besieged by the upsurge of hatred. They should be concerned. In 2014, more than half of all reported racist attacks in France involved Jews.

Their angst has been accentuated by the anti-Jewish attack in Marseille, where Jews and Muslims have lived in harmony for decades.

The lone wolf bigot who attacked Amsellem was an improbable jihadist. He had no history of extremism and exhibited no psychological problems. Consequently, he had not been tracked by French intelligence services as a potential terrorist. Brice Robin, the French prosecutor in charge of his case, believes he was influenced by jihadist websites.

The fact that radical Islam has gained a foothold in Western Europe in general and in France in particular is a worrisome sign that something is seriously amiss. This poisonous phenomenon threatens the safety not only of Jews but of the Muslim community itself. Muslims must ask themselves why Islam is so susceptible to misinterpretation and violence and whether it is in need of a reformation, a process Christianity has already undergone.

In the meantime, France should press ahead with its campaign to root out Islamic extremism and Muslim extremists. In this connection, we applaud the decision by the French consulate in New York City, disclosed yesterday, to sack an employee who crossed a red line with an outrageous post on her Facebook page.

The person in question, Amira Jumaa, is a Kuwait national. Last autumn, in a vicious diatribe sweepingly referencing Jews, she wrote, “You don’t belong anywhere in this world — that’s why you guys are scums and rats and discriminated against wherever you are. Don’t blame it on the poor Palestinians.”

Having exposed herself as a primitive antisemite, Jumaa brought yet more opprobrium upon herself. Addressing the Jewish website that outed her, Jumaa wrote, “First of all, you dispersed rat, I am not an immigrant from France. I am from Kuwait, so my country can buy you and your parents and put you in ovens.”

With this stupid post, she doomed herself. Having already been fired by the consulate, she was expelled from Sciences Po University last December, the first student in more than 140 years to suffer such an ignominious fate.

The lesson here is clear. Racists and terrorists should not be tolerated, regardless of their religion and country of origin. There is no place for such people in France.