Traditionally minded readers of Britain’s Jews, the new book by Harry Freedman, will draw a series of sharp breaths. Every 30 pages or so one of his interviewees utters the heretical thought that Jews worry too much about antisemitism.

On occasion the sentiment comes from an expected quarter. Rivah Brown, who is trying to revive the dying tradition of Jewish leftism via the Vashti website, wants to build a progressive Jewish identity that breaks free of defending Israel (and its occupation of Palestinian lands) and arguments about antisemitism. In recent decades, “the left” has tolerated Jews only if they demonstrate complete adherence to its doctrines. But perhaps Brown will find it has changed. Even if she does not, her argument that there must be more to Jewish identity than chanting old slogans remains open for debate.

The more so because the most unlikely people agree with her. Ezra Marguiles, who grew up in France, tells Freedman that the UK is one of the safest countries for Jews in the world. British immigrants to Israel agree and talk of the paradox that, as British Jews become more confident about asserting their identity, they worry about antisemitism more than ever before.

Freedman is too diligent a writer to state his opinions brazenly. Anyone who has read his account of Leonard Cohen’s spiritual life will know he learned his craft at the “show don’t tell” school of journalism. Freedman doesn’t seek to diminish the abuse of the Corbynite movement. Nor does he underestimate the dangers posed by Islamists and far rightists.

Yet you do not need to read too deeply between the lines to realise that Freedman is perplexed by an apparent contradiction. He looks back to the 20th century when British Jews wanted to keep their heads down and, in the words of the novelist Naomi Alderman “valued absolute invisibility above all other virtues”, and shares the confusion that today’s willingness to celebrate Jewishness is accompanied by so much insecurity.

Telling people to calm down is an attractive idea. Our age of victimhood is apt to forget an old psychological truth. Oppressors from dictators to online trolls want their victims to obsess about them. They may not think about their targets from one month to their next. But they will delight at the news that they have created a near-permanent state of fear and anger.

Meanwhile, social media magnifies hatred — blowing it out of proportion like a fairground mirror. It is the simplest of tasks to pick out one or two posts from venomous cranks and then inflate them into a clear and present danger. Spend enough time online and anyone can convince themselves that they are victims of persecution.

Fear also bestows a kind of glamour. I remember a member of the British Board of Deputies describing how he met a delegation of American Jews. Their impressions of the UK had been formed by the journalism of Melanie Phillips, and the belief hat they were brave men entering hostile territory thrilled them.

“Where’s our security?” they asked, and took a great deal of convincing that a detachment of armed guards wasn’t strictly necessary for the trip from Heathrow.

The more I read, however, the more doubtful I became: and not only because the security at synagogues and Jewish schools is there because of real terrorist threats. Freedman and his interviewees duck the question: if Jews don’t worry about antisemitism, who will?

For all our modern obsessions with Hitler and the Second World War, most people don’t know what antisemitism is. During the Corbyn years, Jewish campaigners realised their denunciations of “antisemites” and “antisemitism” were too obscure for most of the public to grasp. They decided to accuse their opponents of “anti-Jewish hatred” instead. At least their audience could work out what they meant. Clarity in comms, however, risks losing an essential concept that we need more than ever.

The saying that “Jews are the canaries in the coalmine” is a cliché for good reason. The political antisemitism that developed in late 19th century, and the Protocols of the Elders of Zion codified in 1903, has become the justification of far-right, far-left, and clerical fascist regimes and movements across the West and in the Muslim world. It is not only another racial hatred but a deadly theory of power.

Over 150 years, the antisemitic conspiracy theory has jumped from one culture to the next, always adapting while always remaining the same. The appeal to the enemies of liberalism lies in its dismissal of democracy and human rights as conmen’s tricks created by a cabal of Jews who pull the strings behind the facades they build. Modern variants of the lie that will never die include the Trumpist QAnon movement, which imagines an elite conspiracy of Rothschilds running the deep state. Then we have Viktor Orban, who has built his authoritarian power by convincing Hungarians that they are the victims of the Jewish financier George Soros, and the Iranian dictatorship, which blames Israel for the protests against its theocratic rule.

It may be true that Jews should worry less about antisemitism. But it is indisputable that the rest of society needs to worry about it much more than it does.