Violent Islamist attacks on Jews in mainland Europe are causing acute concern. But fanatical religious belief which creates the impulse to murder Jews in the service of God, however appalling and terrifying, is not hard to grasp.What is even more unsettling is that people from the European mainstream, who have gone to great lengths to show they have learned the lessons of the Holocaust, or who display affection for the State of Israel, or who are obsessed with anti-racism and human rights–that such people are now coming out with unhinged Jew-hatred.Two countries in particular are repeating this dismal European history: Britain and Poland.In Britain, the Labour party is in the grip of an existential crisis over the revelation that it is riddled with anti-Semitism. In extraordinary scenes in Parliament this week, Labour MPs rounded on their leadership for continuing to deny the appalling prejudice on display in the party and revealed the threats and intimidation against those MPs who have taken a stand against it.Although much of this bigotry takes the form of obsessional anti-Israelism, even those who hide behind the fiction that blood libels about child-killing Israelis or wild lies that Israel is guilty of genocide or apartheid somehow represent legitimate “criticism” of Israel have been unable to deny the ambiguous anti-Jewish venom erupting in the party, with claims that the Jews were behind Isis and Sept. 11, the Rothschilds control the world’s finances and so on.In Poland, the international uproar over its new law criminalizing any suggestion of Polish complicity in the Holocaust has detonated an explosion of anti-Semitism with accusations of disloyalty or worse being made against Polish Jews. Anna Chipczynska, president of the Jewish Community of Warsaw, has said: “We are receiving anti-Semitic, anti-Jewish statements on a daily basis.”Both in Britain and Poland, however, those accused of expressing or condoning anti-Semitism are genuinely affronted and incredulous at the claim. This because both British liberals and Polish nationalists wrap themselves in fantasies and myths about the purity of their conscience, their heroism or their victimhood. They use these to give themselves a moral free pass for Jew-hatred.It so happens that I have written about historic and current anti-Semitism in Britain and Poland in my recently published novel, The Legacy. In this novel, I have tried to get under the skin of anti-Semitism on both the anti-racist British left and among the Poles. What goes through the minds of such people? Just why do they hate us? Fiction allows one to explore the psychology and the pathology. But I’ve also drawn on my own experience.In Warsaw a few years ago, where one of my books was being published in Polish, I was regaled with what seemed to be genuine affection for both the State of Israel and the Jewish people. I was told this high regard was due to the excellent Polish education system which taught Polish children the unvarnished truth about the Nazi death camps.And what was that truth? Why, that the Jews were murdered in the Nazi camps because they were Poles. Just like the non-Jewish Poles who were murdered alongside them in great number.Denying that the Nazis murdered Polish Jews because they were Jews is, of course, a type of Holocaust denial. But if the Poles were to acknowledge that the Polish Jews were the victims of Nazi Jew-hatred, this would open up the Poles’ own appalling record of anti-Semitism.There were Polish pogroms against Jews before, during, and after the war. Although more “righteous gentiles” saved Jews from the Nazis in Poland than in any other country, many of those heroes were betrayed to the Nazis or murdered by their fellow Jew-hating Poles. In Jedwabne in 1941, Poles—not Germans—rounded up the town’s Jews and burned them alive in a barn.But the Poles ferociously deny this terrible history. That’s because they see themselves as having heroically resisted the Nazis at whose hands so many of them died. They cannot accept that, as undoubted victims of the Nazis, they could also be victimizers of the Jewish people. But they were.In Britain, liberals are in a similar state of denial over their anti-Semitism. This is because they view themselves as anti-fascist and anti-racist and so think it is simply impossible they could be anti-Jew.In fact, anti-Semitism on the left has a long lineage. Marx himself, after all, was virulently anti-Jewish. There’s more to it, though, than just being anti-capitalist or even anti-Zionist. The modern left has junked Biblical morality for libertarian lifestyle choice. And the Jews represent the conscience they are at such pains to deny.I came up against this years ago without realizing the full implications until much later. As I recount in my memoir Guardian Angel, also published recently, when in the 1990s I started writing about the undermining of the traditional family I was called an “Old Testament fundamentalist.” And when in 1982 I first questioned the double standard over Israel at the anti-racist Guardian newspaper where I then worked, I was told that since the Jews claimed moral superiority over everyone else they should be judged by higher moral standards.Despite such attitudes, the left believes that because it stands for the betterment of the world it embodies unimpeachable virtue. Anyone not on the left is therefore not just wrong but evil. Only the right can be anti-Semitic. It is therefore impossible for the left to be so. If they were to admit it, their entire moral and political personality would fall apart.Anti-Semitism, however, is not created by one viewpoint or another. It is a form of derangement which observes no political or cultural boundaries. Whether in London or Warsaw, if it is not recognized as such it will not merely remain a permanent stain on those societies. It will eventually destroy them.