Howard Jacobson: Whatever the faith, someone somewhere has felt the cold edge of its contempt teachers should have been put on a sex offenders list?

It's like watching two schoolyard bullies, suddenly forgetting you are there and belting each other

At last, something that's not the Jews' fault. For the first time in more years than I can remember the world has reverberated to the violence of interfaith rhetoric and no one's mentioned Jewish control of the media, blamed Jewish manipulation of American foreign policy, or burned the Israeli flag. I'm not saying it won't happen, but so far, as the Pope squares up to Islam and Islam squares up to the Pope, there hasn't been a squeak about Zionism. So completely has the Jewish question been sidelined I am starting to feel resentful. A bit anti-Semitic, wouldn't you say, ignoring us to this extent?

In truth, I've been high on it for days. It's like watching two schoolyard bullies, who normally never give you a minute's peace, suddenly forgetting you are there and belting the living daylights out of each other. Schadenfreude isn't quite the word for it. Schadenfreude is for people with no conception of reversal of fortune. You revel in others' adversity only when you are confident your own turn isn't just around the corner. And no Jew of my acquaintance enjoys that sort of confidence. This is why we support football teams who never win. We know that only by tasting defeat every week will we avoid falling into the trap of imagining victory.

Respite is probably the best way of describing it. The opportunity to take a breather and let one's guard down.

But now I'm not so sure it is wise even to do that. Politically, of course, any escalation of the argument between Catholics and Muslims will imperil us all. And philosophically it is foolish to side with one of your antagonists simply because he's in the process of giving a bloody nose to the other.

Misery might acquaint us with strange bedfellows but no good ever comes of lying down with your enemy's enemy. No good morally, no good practically, and no good intellectually. For in the end it is unintelligent not to recognise that wherever towering hatreds collide, all mankind is necessarily implicated. You might hate my enemy but, by the ineluctable laws of hatred, that can only mean you will eventually, if you do not already, hate me.

A Jew, for example, need only consider the language in which Christians have for centuries caricatured Muslims - bestial, sensual, cruel - to recognise the hateful Christian caricature of himself.

Nothing is easier than to jeer at the hypocrisy of both parties to this argument. A Pope lecturing another faith in the matter of violence and unreason! A Pope who has the Crusades and the Inquisition and the small matter of acquiescing in Nazism to show for his church's peaceful intent! And as for those calling for the Pope's execution in retaliation for his daring to accuse Islam of immoderation, the joke is so obvious we hesitate to make it.

And thus we call and counter-call and in the process find ourselves at the making or receiving end of preposterous pronouncement. The stated view of Hammasa Kohistani, the first ever Muslim to be crowned Miss England, that moderate Muslims are turning to terrorism because they feel they might as well, since they are being stereotyped as terrorists anyway, is troubling until we remember that beauty queens are not chosen for their ability to think reasonably.

But when Muhammad Abdul Bari, the new secretary general of the Muslim Council of Great Britain, says the same thing, warning that our "demonisation" of Muslims will result in two million more Muslim terrorists to deal with in this country alone, we are stupefied.

The blackmail aside, are we really to believe that a Muslim will blow up a train for no other reason than that he is suspected, or believes himself to be suspected, of intending to blow up a train? Is calumny all it takes to make a terrorist? By that logic, medieval Jews charged with ritually murdering gentile babies for their blood - a libel still promulgated throughout the Arab world today - should have gone out and done the thing of which they stood accused. Why not? You stigmatise us as baby-killers, so baby-killers we will be.

Having got which off my chest, what good does it serve? We were doing nicely without Jews on the agenda, and I gratuitously bring them back. Impossible not to, you see. I have to show a Muslim how a Jew thinks. Behold my moral code: I am not demonised into violence.

Comes back the Muslim: "You do not need to be; your violence is evident in Lebanon." Comes back my response: "But ours is not in essence a militaristic faith. It is other people's bloody-mindedness that has bloodied us. Unlike some I could name, we do not confuse the spiritual with the martial. As Pope Benedict XVI says..."

At which point I don't blame any Muslim for telling us all where to get off. There is no profit, it seems to me, and certainly no future - literally no future - in seeking out the essences of one another's faiths, now accusing that one of inherent violence and intolerance, now praising ourselves for the intrinsicality of our humanity. We will find what we want to find.

No national or religious mythos comes without aggressive self-definition or belittling dismissal of the fearful other. Both Islam and Christianity are proselytising, imperial relig- ions, believing that the swamplands of primitivism and ignorance that lie beyond them must be conquered or missionised into truth. Judaism, as it happens, is more tolerant. Believe what you like, we say. Which can be construed as separatist arrogance. Whatever the faith, someone somewhere has felt the cold edge of its contempt.

As every schoolboy knows, or used to know, a barbarian was to a Greek whoever was not Greek, was to a Roman whoever lived beyond the pale of Roman civilisation, is to a Christian or a Muslim whoever is not a Christian or a Muslim.

We are all barbarians to one another. Now, though it means my relinquishing my not-quite schadenfreude, can we please shut up about it.