When is a genocide a genocide? The word is much in vogue, though its precise meaning – the intentional destruction of a people – is hard to justify in the case of Israel’s bombardment of Gaza, which, though without doubt brutal in execution and heartbreaking in effect, falls a long way short of any ambition to exterminate an entire population. Genocides don’t leaflet the populations they want to destroy with warnings to stay out of harm’s way, and Hamas, which Israel avowedly does want to see the back of, is not the Gazan people. For all the sensationalist pronouncements of academics who specialise in genocide, ethnic cleansing, apartheid, settler-colonialism, etc, the words simply flutter like so many pennants at a medieval joust. Denoting, in the fading light, which side you’re on, no more. The only party to a declared intention to commit genocide is Hamas. It is a matter of contention whether the chant “From the river to the sea” is also genocidal. But perhaps the circumstances allow for hyperbole. To accuse its enemies of wanton exaggeration is not to exonerate Israel. There has to have been, and there will need to be, a better way of securing peace for the country than the assertion of military might. But brutality isn’t genocide. Words matter in war, and when a vocal third party to a war operates from the campuses of western universities, where words go off like hand grenades, we must be careful which we choose. Among the casualties of this war are the young, who are susceptible to lurid language and who get their disinformation from the internet and their rhetoric from their professors. We have been here before but with this difference: the vilification of Israel is more scurrilous and orchestrated this time because on 7 October Hamas breached not only a fence but a decorum that in the past has marked us out as civilised. We don’t – we didn’t – turn the traumatic history of a people into a justification for hating them. Post 7 October, we can say things about Jews we haven’t dared say before. At last, we can throw the Holocaust back in their teeth. Some years ago, I borrowed the title for a lecture from the English philosopher John Gray. “It has long been known,” he wrote in his book Straw Dogs, “that those who perform great acts of kindness are rarely forgiven. The same is true of those who suffer irreparable wrongs. When will Jews be forgiven the Holocaust?” That deeply disturbing question, to which the implicit answer is a terrifying “Never!”, began to explain to me the recurrence of Holocaust denial in one guise or another, from outright refusal to believe the Holocaust had ever happened to condemnation of the Jews for not properly learning the lessons of the camps and graduating from them with first-class honours degrees in human kindness. It has grown common to accuse Jews of “weaponising” the Holocaust, as if banging on about it distorts its essentially peaceful nature. By exhuming the Holocaust, the argument goes, Jews claim exemption from the obligations that constrain everyone else. And that which you seek to profit by, you lose the right to. Charging Jews with genocide is a sophistication on that theme, painting them as perpetrators of the very crime that killed them in their millions, as a consequence of which that crime is abrogated. There is a sadistic triumphalism in charging Jews with genocide, as though those making it feel they have their man at last. The sadism resides, specifically, in attacking Jews where their memories of pain are keenest. By making them now the torturer and not the tortured, their assailants wrest their anguish from them, not only stealing their past but trampling on it. The sadism of Holocaust denial has been a long time evolving. Calling Zionist Jews Nazis was an early go at discrediting them, inversely, by equating them with their murderers. Accusing them of harvesting the organs of Palestinian children, thereby invoking Josef Mengele’s experiments on Jewish inmates of Auschwitz, was a similar attempt to blur the lines between doer and done-to. But the genocide charge goes further than any of those. For the Nazis, “genocide” wasn’t a verbal flourish. “Final solution” meant “final solution”. Show that Jews intend a final solution on someone else, and we can fancy a retrospective justice to have been at work – the Jews being punished for a crime they were yet to commit. Call this Holocaust annulment. Morality changed on 7 October. Black became white, evil good, ugliness beauty, the victim the culprit. It was Hamas’s genius to have seen something to its advantage in the declining status of the Jews in the conscience of the west. It realised how the drip, drip, drip of unremitting revilement in the western media and on western campuses had worn away their humanity. How sympathy had wearied and turned to scorn. How the west was of a mind to expunge its guilt. It’s not unknown for the left to rejoice in acts of violence that lend brawn to its paper theories and then soul-search when that violence makes the world worse than it was before. Coming from the other political extreme, the American satirist Tom Wolfe called such political slumming “radical chic”. To describe the current revulsion from the Jews in favour of a terrorist group that kills and rapes and mutilates, I propose the less catchy term “metaphysical chic”. That the respectable sometimes lose their hearts and reason to hardened criminals we know from the newspapers, and that the virtuous find it thrilling to go still further and bow the knee to vice, we know from the novels of Dostoevsky. Perhaps no writer better understood the perverse exhilaration of impiety. When, for the sheer irreligious hell of it, we begin withdrawing fellow-feeling from Jews, upturning the moral universe and declaring them guilty of what was done to them, this impiety shows itself first as thinking the unthinkable, then as saying the unsayable. It is impossible not to ask – how long before we do the undoable? Howard Jacobson is a novelist, broadcaster and university lecturer