When the historian Lewis Namier was asked why, since he was a Jew, he didn't write Jewish history, he replied: 'There is no modern Jewish history, only a Jewish martyrology, and that is not amusing enough for me.'

Out of martyrology grows demonology. Put it how you like: worms turn, ugly ducklings become swans, victims acquire a taste for perpetration, cowards decide it's time to be heroes. The late and seldom lamented Meir Kahane, to whose ultra-orthodox militants Baruch Goldstein attached himself, understood the emotional logic of such a transformation and, in Philip Roth's fictionalising of him at least, predicted the response to it: 'First it was the Jewish sickliness that was abhorrent to all the robust Aryans, frail Jewish men with weak Jewish bodies lending money and studying books - now what is disgusting are strong Jewish men who know how to use force and are not afraid of power.' Wherever one stands in relation to this progression, it is clear that 'Never Again' - the universal post-Holocaust protest - cannot be a promise of a fresh start. The roundabout doesn't stop. What happened to you yesterday determines what you will do tomorrow. And if you understand history pre-eminently as a saga of things happening to you - martyrology - then any intervention in history on your part is bound to be muscular.

It's unlikely that Lewis Namier would have found this reversal any more amusing. The catch of being Jewish - however un-Jewish you would wish to be - is that you are always implicated. I have tampered with that anecdote about Namier. What actually happened was that Lord Derby said to him: 'Namier, you are a Jew. Why do you write our English history?' Our English history. It's in the light of that emphasis that the violence of Namier's rejoinder (a rejection of a rejection) has to be understood. No Jew who is not a follower of Meir Kahane wants to be confined to a single Jewish story, or cares to be reminded that he is accepted into other cultures on sufferance. Philip Roth's fanatic is alive on the page because he is able to disarrange the strings with which even the most disengaged Jew is strung.

The fanatics I met in the flesh, when I was writing and filming Roots Schmoots in Israel, lacked the benefit of having their lines scripted for them by a great novelist; but they were expert, none the less, in the manipulation of my unease, my scruples, my last nationalist compunction. They were alien to my intellect but they were somehow familiar - just call it a Jewish thing - with the topography of my heart. And that (for what else is fanaticism for?) they were only too happy to rip apart.

On a little bench outside the children's playing area in a settlement on a stony hill overlooking Hebron, a beautiful woman in a touch-me-not fedora, who blushed when I complimented her on how young and well she looked for a mother of 14 children, put her thumb and forefinger almost together, allowing but the most fractional sliver of light between, and said: 'This little, tiny, tiny '

She was talking about Israel. The map. The borders. And even the ambition. Tiny, tiny - the unprepossessing scrap of land Jews were prepared to die for. Tiny, tiny - the inroads made into the vast continent of Arabia. Who could deny us, after what this one had done and after what that one had done, this tiny, tiny crumb of cake? I agreed with her. Who could deny us? Tiny, tiny - the thing we sought. But grant her that, only grant her that, and the next stage is transfer of all Arabs from Judea no, not killing, she could not bear it the other day when she heard Jews chanting 'Death to Arabs]' no, not that, that wasn't Jewish, Jews didn't believe in that but transfer, encouragement to go away from our little home and stay away from our little home, that was different. Call it separation. See it as the thing couples do when they are not in love any more. Heartless, did I think? Under her fedora, a slow, sad smile, the smile of the mother of generations, the mother of a tribe, my tribe. Heartless? Would we have minded had Hitler offered us transfer and separation instead of the other thing?

Hitler, Hitler, always Hitler. You hear the name Hitler more often in Israel than you hear the name of God. But then we saw more of Hitler than we saw of God, didn't we?

'Would you stay at a hotel run by Hitler?' a maniacal Brooklyn born-again asked me in Jerusalem, after I'd confessed to staying in a hotel run by Arabs.

I remember laughing. But he had hold of my sleeve and was pulling at me. 'Whose life is more important,' he asked me, 'mine or Hitler's? If Hitler is coming at me with a gun, don't I have the right to defend myself?'

After the martyrology, the demonology. There are a lot of people in Israel dreaming of killing Hitler. Most of them American. Most of them from Brooklyn. And here is a fact indispensable not just to our understanding of Baruch Goldstein's actions but to Israeli extremism in general - it may be couched in the language of the Old Testament, but its accent is North American. I don't know whether Baruch Goldstein was born Baruch. There's a fair chance he wasn't. You meet Baruchs by the barrow-load in the medieval messianic boroughs of New York, almost all of them originally Daniels and Irvings. American returnees to ultra-orthodox Judaism give themselves names such as Baruch (Channa, if they're women) in order to re-Hebraise themselves. Spiritual idleness, you see; idleness not available to you if you are an Ethiopian Hebrew wandering Israel in a sheet, or a Jew from Eastern Europe at a loss to comprehend the brave old world of mutilation and peasant-costume you are being enticed into re-entering. Free of the ghetto at last, the Brooklyn Baruchs construct a ghetto of the mind. Safe - safe as you can ever reasonably expect to be - from anti-Semitism, they create an environment in which they can walk in fear again.

Now bring such a Baruch - American-born, born into shoot-outs in shopping malls and sects confusing self with sanctity - away on a Cook's Tour of the Soul to a real hunky-dory Disneyland New Jerusalem, all guns and God, and it should be no surprise that he runs amok along the frontier. Settlements may be the 'facts on the ground' that all attempts at peace have now to stumble over, but settlers themselves - more commuters than pioneers - are dangerous not by virtue of where they choose to live but because of the spiritual vagabonds who have chosen to live among them.

But those of us who would wish to see the Hebron massacre as an accident of Jewishness, an act which every habit and principle of Judaism abominates, are not yet off the hook. 'Better to be numbered among the persecuted than the persecutors,' I said, quoting the Talmud, whenever the next holy fanatic offered to take me through his or her plans for the extermination of the Arabs and the subsequent burning of all places of worship that were not Jewish. Never mind the looks of incomprehension that passed across their faces, or their correction of my interpretation of those Talmudic words. They already had numbered themselves among the persecuted. That was the message of the beards the men grew, and the fuzz and the side-locks and the fringes, and the snoods the women wore so as to quieten the loins of strangers who beheld them. And that was the meaning of the settler ambition itself - to be one of few against the many. They had numbered themselves among the persecuted in order that they then might persecute. And you can't blame that moral contortion on the Americans.

Is there, then, a peculiar Jewish tortuousness at work here, after all?

Baruch, wouldn't you know, means blessed. You can hear Torah in it. Study. Learning. Peaceableness. So by what method have those faithful to the memory of Baruch Goldstein, those rabbis who have committed the blasphemy of valuing one man's blood higher than another's, been able to reverse the meaning of his name? How does blessed come to mean accursed? And how are those who send a blessed word on an accursed errand able to convince themselves of their holy purpose?

There is a Yiddish expression I remember hearing often when I was small. Dray nicht mein kopf. A draykopf is someone who mixes up your head or is so busy trying to mix up your head that he mixes up his own. A draydel is a spinning top. When your father asks you not to dray his kopf he is asking you not to treat his brain like a draydel. But this, of course, is a contradictory order since you are brought up, as a Jewish child, to spin as many brains as possible. At the age of six, I was master of every puzzle and conundrum that the sleepy commercial world of that time could devise; when I showed my parents' friends what I could do, as I was encouraged to on every occasion, they held their temples with the pain of it. And that became the only sign of appreciation I valued: someone holding the sides of his head with the pain of what I'd just put his brain through. Read the Talmud and you'll see where this love of kopfdrayenish comes from. Subtle distinctions, punctiliousness pursued until it's torture, rabbit-warrens of allusiveness, verbal chicanery, intellectual perseverance so conscientious that you cry out to be allowed a moment's sloth. When the Jewish intellectuals of the enlightenment came out from the study, rubbing their eyes, they cursed the overwrought fastidiousness and the passion for reversal to which centuries closeted with the One Book and its commentaries had damned them.

And now, if the rabbis have their way, we are to be back with the One Book again. Back with the literal word of God, His plans for the Jewish people - plans which the likes of Baruch Goldstein are incited to execute - and the vertiginous inversion of plain reasoning. 'The greatest of tragedies,' said Meir Kahane, after Alan Dershowitz had argued Kahane's right to free speech, 'is that there are those who would grant me the right to speak because they would also grant the right of speech to Yasser Arafat ' That hurt your head? There's sense in there if you look for it. Better I don't speak than that my enemy be allowed to speak as well; what value freedom for me if my enemy is an equal beneficiary of it; what value freedom at all if it is not granted solely to me? That kind of sense.

At a meeting of God-driven lunatics in Jerusalem - most of them from Brooklyn - I dropped an injunction from the Torah: 'Love ye therefore the stranger: for ye were strangers in the land of Egypt.' I didn't hold out much hope for its safe passage, but you have to try. What I didn't expect, though, was a flurry of expositional subtlety. I'd got it wrong. I'd taken as the right way up something that was upside-down. What the Lord was actually saying was, love ye therefore the stranger, so long as he's Jewish.

I am drawn, I confess, to something in the tortuousness of the religious Jewish mind. Let's not be coy about it: I am drawn to what happens to it when it ceases to be religious. When it finds its way into Jewish humour, that most marvellous of all strategies for intellectual survival; when it finds its way into art made by Jews, and into literature and into music and into thought. It still hurts the head, of course; it still stands accused of mental cruelty. But in art we call that challenge. This is the redemption of our labyrinthine moral sense, our spinning-top intelligence. What we dare not do is let it fall back into the hands of the rabbis. Those who think they can reverse the meaning of the word God itself.

Howard Jacobson's book 'Roots Schmoots - Journey among Jews' has just been published in paperback by Penguin at pounds 6.99.

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