David Irving, the British historian who was jailed for three years on Monday by a court in Vienna under a law that prohibits Holocaust denial, does not, on the face of it, have much in common with Dr. Rowan Williams, the Archbishop of Canterbury.

In English-speaking countries, where Holocaust denial is not a crime per se, Mr. Irving’s sentence has aroused anxiety lest he portray himself as a martyr for free speech; the Austrian prosecutor, however, has appealed for a longer sentence. Mr. Irving forfeited any scholarly reputation he may once have had six years ago when he sued the American historian Deborah Lipstadt in London for libel and lost. The whole corpus of his work was dissected in court and the judge branded him a Holocaust denier, a liar and an anti-Semite. Mr. Irving was ruined by the L3 million costs, but he remains a hero to neo-Nazis and such fringe groups as the “Real History” Festival in Cincinnati.

Dr. Williams, on the other hand, is an eminent Oxford theologian, the lynchpin of the worldwide federation of churches known as the Anglican Communion, which includes American Episcopalians, and a pillar of the British establishment. Above all, Mr. Irving is an apologist for Hitler; Dr. Williams is an apologist for Jesus Christ. A starker contrast – socially, intellectually, spiritually – would be hard to imagine.

Yet the views of both men belong on a single ideological continuum. At one end of this spectrum are those who deny the Holocaust, yet live for the day when they can resume Hitler’s “Final Solution” by wiping Israel off the map. Those who are to be found at this end of the continuum include Hamas, who have just taken over the Palestinian Authority, and the entire Iranian leadership: the President, Mahmoud Ahmadinejad, and the Supreme Leader, Ayatollah Khamenei. An unknown but substantial proportion of other Muslims, especially in the Middle East, Africa and Asia but also in the West, are also to be found at this end of the scale.

There, too, are the neo-Nazis, fascists and racists of various stripes, from Louis Farrakhan to Jean Marie Le Pen. So, too, are those pseudo scholars who attempt to give anti-Semitic conspiracy theories a spurious intellectual respectability, among whom is Mr. Irving. He was apparently hoping to attend a conference in Teheran, where Mr. Ahmadinejad actively promotes Holocaust denial, when he was arrested. A Nazi-Islamist rapprochement seems to be taking place, notably in France.

A little – but only a little – further along the continuum are the Left-wing anti-Semites: the ex-Communists, along with their ex-fellow-travelers, and the “anti-Zionist” agitators who flourish on campuses throughout the Western world. They too make Faustian pacts with the Islamists. Few are Christian, fewer Jewish. But Edward Said was one of their heroes; Noam Chomsky is another.

At the other end of the spectrum are the illiberal liberals who claim to be friends of Israel, while in practice giving aid and comfort to its enemies. In this category – Lenin’s “useful idiots”- both Christians and Jews are numerous. Among them is the Archbishop of Canterbury.

Earlier this month, the General Synod of the Church of England voted to sell its stock in corporations that supply equipment to the Israel Defense Force; in particular, Caterpillar bulldozers used to demolish the homes of Palestinian terrorists. This was a purely symbolic gesture: the Church’s investments are managed by commissioners who are answerable to Parliament, not to priests.

In the United States, religion is in theory a private matter. But in England everybody, Anglican or not, has a stake in the established church. All are entitled to be baptized, married, and buried in one of the thousands of deserted churches that it maintains. The Archbishop of Canterbury crowns the monarch, advises the Royal Family, and speaks on behalf of all faiths.

In general, Anglican priests pay little attention to the rest of the world and the world pays little attention to them. They seem happiest quarrelling about gay bishops. But when the Church hierarchy voted to treat Israel in the same way that it once treated South Africa in the days of apartheid, the gesture provoked a strong reaction among British Jews.

The Chief Rabbi of Great Britain, Sir Jonathan Sacks, declared that the Synod vote was “ill-judged even on its own terms” at a time when “Israel faces two enemies, Iran and Hamas, open in their threat to eliminate it.” “The Church has chosen to take a stand on the politics of the Middle East over which it has no influence, knowing that it will have the most adverse repercussions on a situation over which it has enormous influence, namely Jewish-Christian relations in Britain.”

Sir Jonathan Sacks is no less eminent a scholar than Dr. Williams and a gentleman in every sense of the word. He is slow to anger, as the Bible puts it. So by his standards, this was fighting talk. The Archbishop, a friend of the Chief Rabbi, was alarmed by the tone. But his response – addressed to “Dear Jonathan” – was as unctuous as it was disingenuous.

Though he had voted with the majority, the Archbishop admitted only that he “had been present.” He wrote that to register “deep unease” about Israeli policy was “emphatically not to commend a boycott, or to question the legitimacy of the state of Israel and its rights to self-defense; least of all is it to endorse any kind of violence or terror against Israel and its people, or to compromise our commitment to oppose any form of anti-Semitism at home or abroad.” Heaven forbid that any member of the Synod “would have an instant’s sympathy with any such hostility to the Jewish people or the State of Israel as such.”

Yet the decision by Dr. Williams and his colleagues to treat Israel as a pariah sends a very clear signal to the world, especially the Palestinians. They have just elected a Hamas government that is not only committed to the annihilation of Israel, but also endorses the “Protocols of the Elders of Zion,” claims Jews were behind both world wars and control the United Nations, proclaims Islam’s global hegemony over Jews and Christians, and calls on Muslims to join in global jihad. This ideology is ignored by Dr. Williams and his Synod. They propose instead to deprive Israel of the means to retaliate or defend itself against such enemies. Islamists everywhere will conclude, reasonably enough, that Anglicans blame Israel for the jihad against the West, and that they certainly wouldn’t go to war to prevent a second Holocaust.

I am not sure which is worse: the Nazi David Irving, who at least goes to prison for his odious creed, or the liberal Archbishop Williams, who insists that some of his best friends are Jews.