In 2002, on the BBC TV show Question Time, I was accused of dual loyalty in front of a jeering studio audience. My crime had been to defend Israel against demonization and double standards by both the audience and other members of the panel.At that time I had visited Israel only twice in my life, two years previously. No matter. A British Jew defending Israel was – and is – immediately accused in some quarters of incipient treachery toward Britain, just as throughout history antisemites have accused Diaspora Jews of dual loyalty or treachery merely because they are Jews.I thought of my own experience, of course, when I read the report on antisemitism in the UK published this week by the Institute for Jewish Policy Research.There is currently much disquiet over the Labour Party’s conspicuous failure to address significant antisemitism within its ranks. But there has long been far wider concern among many British Jews about the antisemitic discourse, harassment and physical attacks which have become sickeningly commonplace in Britain over the past few years.The report’s author, Daniel Staetsky, describes a situation which is complex.Only around 5% of the population are out-and-out antisemites holding multiple anti-Jewish attitudes. Nevertheless, about 30% subscribe to some kind of antisemitic views.The key is Staetsky’s distinction between antisemites and antisemitism. For while the number of antisemites is very small, the amount of antisemitism diffused throughout British society is much greater. That’s because, while people may not feel personal hostility toward Jews, they may believe certain things which are in themselves antisemitic. As Staetsky says: “Antisemitic ideas are not as marginal in Great Britain as some measures of antisemitism suggest, and they can be held with and without open dislike of Jews.”As a result, the probability for a British Jew of encountering “potentially offensive or, at the very least, uncomfortable” views is about one in three. That’s high.Staetsky states, however, that 70% of British people hold a “favorable” attitude toward Jews. He reaches that optimistic figure, though, only by reducing respondents’ options to categorize their attitudes. When offered more options, the scenario for British Jews becomes less rosy: only around 39% have “somewhat” or “very” favorable opinions of Jews, more than 5% are classed as “somewhat” or “very” unfavorable and nearly 56% are classed as neither favorable nor unfavorable or as “didn’t know.”Two groups are shown to be principally responsible for problematic attitudes: Muslims and the Left.While “significant proportions of Muslims reject all such prejudice,” antisemitism and anti-Israel attitudes are two to four times higher among Muslims than in the general population.And contrary to the claim by those on the Left that they can’t be antisemitic because they are opposed to racism and fascism, the report says levels of antisemitism on the Left are “indistinguishable” from in the rest of the population. When it comes to Israel, however, the Left is worse. Even those who are “slightly left-of-center” or “fairly left-wing” are more anti-Israel than the general population, while the more left-wing people are the more they hate Israel. You don’t say!Moreover, says Staetsky, while only 12% of the population are out-and-out Israel-bashers, close to a quarter of Britons believe, to some extent at least, that Israel is deliberately trying to wipe out the Palestinian population, and about one in five that Israel is an apartheid state. These are huge numbers for such poisonous lies. And no fewer than 56% hold at least one anti-Israel attitude.So as Staetsky says, the feeling among so many Jews that they encounter anti-Israel positions all the time becomes immediately comprehensible.The true extent of antisemitism has, of course, been masked by claims that being anti-Israel is not the same as being anti-Jew. Staetsky, however, states: “The existence of an association between the antisemitic and the anti-Israel attitudes tested is unambiguous.”Moreover, the stronger the hostility to Israel the more likely it is to be accompanied by antisemitic attitudes such as that “Jews exploit Holocaust victimhood for their own purposes.” And that correlation puts left-wing Israel-bashers squarely in the antisemitism camp.Staetsky makes the link solely through a statistical overlap between anti-Israel and antisemitic attitudes. I’d go further. Anti-Israel discourse has exactly the same unique characteristics as antisemitism.Both are based entirely on lies, distortions and libels, double standards, obsessive hatred and the assumption of a covert conspiracy with an almost supernatural cosmic power to do the world harm. And that’s no coincidence.People don’t understand that the demonization of Israel isn’t merely “criticism.” Nor do they understand that antisemitism isn’t just an expression of dislike or hatred. Both are instead a particular form of derangement – a repudiation of reason and the replacement of truth by paranoid and malevolent lies.Many Israel-bashers have no idea that what they are saying is profoundly antisemitic, because they have no idea that it is a set of deranged lies.That’s because they never hear the truth. And that’s above all due to the failure of Israel to make its own case in an intelligent and strategic manner.The report makes clear that far-right adherents, although among the most antisemitic, are of negligible importance because there are so few of them. Of far greater concern is the Left which dominates British society. And that’s what’s making Britain so uncomfortable now for so many Jews. Melanie Phillips is a columnist for The Times (UK).