'I hate the Jews," I heard someone say in a queue the other day. It's possible I misheard and that what he really said was "I hate to lose." Or conceivably, "I ate at Waterloo."

I asked the person I was queuing with if she'd heard anything. She had. "Highgate, at two."

This will remind you of the scene in Annie Hall when Woody Allen grows alarmed at what someone has just asked him – "Djew eat? Not, did you eat, d'you eat, but Djew eat? Jew!"

It is a source of great comic consolation to Jews to recognise their paranoia and make light of it. People who don't like Jews find it a bit self-referentially cute. But we'll make light of that too. If one Jew tells another that he has just had his article rejected by the editor of a secularist magazine, the anticipated response is: "Anti-Semite, is he?" And if the suspected anti-Semite turns out to be Jewish, that's perfect. It completes the circle of absurdity.

Which is not to say, however . . . and you know what it is not to say. Just because we invent monsters of Judenhass to satisfy our psychic need for them, does not mean they do not exist. Yet paradoxically it is often when the fear is greatest that we speak the least about it. If there is one thing Jews know from experience, it is that loudly decrying anti-Semitism wins few friends, and might well create the very conditions in which anti-Semitism prospers. In his book British Jewry and the Holocaust, Richard Bolchover charts the reluctance of British Jews, in the last years of the war, to raise a hue and cry about what they knew was happening in the camps, for fear of risking their own status. "Stay shtumm," was the advice given to me when I was growing up. Don't draw attention to yourself. If we feel safer today than we did sixty years ago, there remains a conviction of precariousness, a sense that it is better not to rock the boat.

So finding anti-Semitism at once comes easy and comes hard to us. By the logic of the above, you would have to say that the more of it we have the luxury to say we are finding, then the less there probably is to worry about. A consoling thought. But the truth of it is – and I find no consolation here – that we are perplexed by a new phenomenon, or, if you like, an old phenomenon in a new guise: not Jews qua Jews, but Jews as Zionists, not Jews as the enemies of Christianity, but Jews (still hooked-nosed and usurous, curiously) as the enemies of Islam. Israel, which was meant to change everything for the better, has changed everything for the worse.

It is an odd sensation to be a Jewish writer at the moment and to discover that no one reads you more keenly than extreme Muslim propaganda groups monitoring world Jewish hegemony. It would be flattering if it were not frightening, and if the interest extended beyond what you have to say about Israel. When I do mention Israel in any article I write for the press I am assailed by vitriolic response, not primarily, I have to say, from Muslims. And though most of my correspondents are initially at pains to explain it is Israel and not Jews with whom they have a quarrel, it is not long before they are invoking Jewish aloofness and arrogance, Jewish supremacism (of which Jews being better at grammar is one example cited to me recently), and of course Jewish influence.

This is why I grow weary when people tell me it is not anti-Semitic to criticise Israel. Of course it isn't. Not for a moment did I ever think it was. Or at least not until I received letters from those whose anti-Zionism bore no essential difference from anti-Jewishness in its purest medieval form. And whether you are the recipient of such letters or not, it is dangerous naïvety not to imagine that regulation anti Semitism would find its opportunity in the mantra "It is not anti-Semitic to criticize Israel", and wilful intellectual blindness not to see the simple syllogistic snare it conceals. The countering formulation has to be along these lines – no, you are not necessarily anti-Semitic because you criticize Israel, but that is not to say you necessarily aren't. All men are not villains. But some villains are men."

The give-away, in helping to decide the matter either way – leaving aside blitheness in the matter of the victims of suicide bombers – is the temperature of the vocabulary. No one who is not anti-Semitic, it seems to me, would ever see the justification of charging Israel with Nazism. If the unfairness of the combat is what strikes you, the unbendingness or cruelty of Israel, there is a plentiful vocabulary of condemnation to be drawn from colonialism, territorial opportunism, or mankind's long experience of the dehumanizing effects of war. The charge of Nazism, on the other hand, can be understood only as an insult delivered not to Israel's policies but its Jewishness, finely calibrated to remind Jews of their greatest loss, and to imply, by a sort of backward logic, that we are at liberty now to construe it as deserved. To those who do, shall it have been done.

After Holocaust denial, post hoc Holocaust justification.

There is an obduracy in anti-Semitism. Among mankind's many arguments with itself is one in which the Jews have somehow found themselves, or maybe have chosen to find themselves, implicated. It bears on reason versus instinct, nature versus intellect, what Nietzsche called the aristocratic principle versus the democratic. Wagner's music sings exquisitely of this eternal tussle. Or at least sings exquisitely of winning it. We are only safe, though, as long as no one wins, and the argument is allowed to go to and fro. But at present many of those you would expect to value the ongoing disputation – academics, writers, journalists, etc – have seized on Israel as a justification for giving way to the ecstatic Wagnerian music in their souls. This fills me, and other Jews of my acquaintance, with a deep philosophical despondency, which is not, I grant you, the same as being frightened on the streets (which we are not). But the fires that begin in men's minds spread quickly and are not easily put out.