Contemporary anti-Semitism offers us a stunning paradox. Never has it seemed so unfashionable to be an anti-Semite, so politically unacceptable and incorrect, even beyond the pale. And never, since 1945 have Jewish communities been so fearful of its eruption and the State of Israel so concerned about it. The official consensus is amazing, almost too good to be true. Successive Popes have condemned anti-Semitism, using terms like "never again". Governments fight it and some even legislate - especially against Holocaust denial. The Organisation for Security & Co-Operation in Europe (OSCE) has organised successive conferences against it - in Vienna, Berlin, Cordoba and Bucharest. The US State Department is obligated by Congress to monitor anti-Semitism. In the UK, a parliamentary committee issued a detailed report on it. The Israeli Foreign Ministry has also begun seriously to address the subject and now sees it as an element of policy, international relations, state-to-state relations. And I was interviewed not long ago on Al-Jazeera, the Arab news TV channel, and given every opportunity to refute the Holocaust-deniers and even to discuss Arab anti-Semitism. So what is going on?

Is it not remarkable that in the European Union (which some call Eurabia) so many government leaders and officials are eager to pronounce their abhorrence of racism, anti-Semitism, Islamophobia and xenophobia, though levels of Jewish anxiety about Jew-hatred have never been so high since 1945? Is it not ironic that the memory of the Holocaust is so frequently and respectfully evoked - especially by European politicians, intellectuals, academics, journalists, churchmen and shapers of opinion - at the very time when Israel-bashing has become a Europe-wide popular sport which has achieved global resonance? And how is it that the UN solemnly commemorates the Shoah yet remains - despite some improvements - a world forum for vicious anti-Zionist incitement against Israel?

There is no single, monolithic anti-Semitism that we face in all these cases, but rather a cluster of loosely related phenomena - some of them irritants of the common cold variety and others potentially lethal. I do not believe there is a single master strategy to deal with these disparate ailments. But establishing priorities is clearly important. One obvious point is that we have to take into account national differences - the specific challenge in each country will necessarily reflect its history, culture, politics and the character of its Jewish communities. Another is that Jews cannot fight anti-Semitism alone - they need allies who will change response to the specific type of anti-Semitism and the conditions prevailing in a given society.