What would Jabotinsky do? That’s the question I keep coming back to as France emerges from the demonstrations of Liberté, Égalité, Fraternité in the wake of the carnage at Charlie Hebdo and the killings at the kosher supermarket.

Vladimir Jabotinsky was the leader of what might be called the hawkish wing of the Zionist movement. For years before the Holocaust, he gave speeches around the world warning that Jews needed to get out of Europe. He called urgently for bringing 6 million of them to Palestine.

The left jeered at him and called him a fascist. But today he’s widely seen as a prophet.

What would he counsel the Jews of France today? He’d call on them to get out while they can and move to Israel, for sure. But what can France possibly do to reassure its Jews? There, I’d recommend Jabotinsky’s 1923 essay “The Iron Wall” — one of the most famous works of journalism of the 20th century.

Jabotinsky was writing about Zionism and the Arabs. But he might just as well have been writing about France or any other country in an existential struggle with a zealous minority. “I am reputed to be an enemy of the Arabs, who wants to have them ejected from Palestine, and so forth,” he wrote. “It is not true.”

Indeed, he felt it was “utterly impossible to eject the Arabs from Palestine” and that there would “always be two nations in Palestine.” But Jabotinsky always insisted he wanted “equality of rights.”

He went so far as to write that he was “prepared to take an oath binding ourselves and our descendants that we shall never do anything contrary to the principle of equal rights, and that we shall never try to eject anyone.”

What prescient advice for France, particularly after it has absorbed a million Algerians and at a time when politicians across much of Europe, from Germany to Sweden to England, are starting to talk about forcing Muslim immigrants to leave. That’s not Jabotinsky.

Where his hard line showed was over another question — “whether it is always possible to realize a peaceful aim by peaceful means.” That, he argued, was up to Israel’s enemies. And the same point can be made in respect to France.

This is where the Iron Wall comes in. Jabotinsky came to the view — one vindicated in the seven-plus decades since he died in 1940 (at a training camp for his followers at Hunter, NY) — that there could be no “voluntary agreement” to end the dispute between Jews and Arabs.

It didn’t matter, Jabotinsky reckoned, whether one tried the carrot or the stick.He contrasted such historical figures as Cortez, Pizzaro and even Joshua, who behaved like “brigands,” with those, like “the Pilgrim Fathers,” who “did not want to do harm to anyone, least of all to the Red Indians.” Both approaches wound up meeting resistance.

Jabotinsky was for putting up an iron wall. Meaning, a defense force and policy that would be impossible for enemies to breach. He warned against peace talks as any real answer. “We keep spoiling our own case, by talking about ‘agreement,’ ” he wrote, a reference to parleys in the 1920s.

“We hold that Zionism is moral and just,” Jabotinsky wrote in the most famous sentences of his career. “And since it is moral and just, justice must be done, no matter whether Joseph or Simon or Ivan or Achmet agree with it or not.”

If France believes itself moral and just nation, and if it wants to keep its Jews, it will have to stand its ground — to maintain its values of free speech and free religion, defend its Jews and halt its appeasement of their enemies — without apology.

And it’s going to have to support unambiguously Israel’s right to do the same. It will have to reverse Charles de Gaulle’s decision to tilt France to the Arab side after the 1967 war.

Jabotinsky is not some rarified, irrelevant figure. The Likud party, whose leader Benjamin Netanyahu is prime minister of Israel, is headquartered in Jabotinsky House. Bibi was marching side-by-side with President Francois Hollande just this week.

Jabotinsky never suggested peace was impossible. But, he predicted, no agreement could come voluntarily. It could come only when our enemies have “no longer any hope of getting rid of us, because they can make no breach in the iron wall.”

This column first appeared in the New York Post.