"I've read countless books on the subject, and no one has been able to explain the persistence of anti-Semitism," Supreme Court Justice Elyakim Rubinstein said this week, at the Foreign Ministry-hosted Global Forum for Combating Anti-Semitism. It is, indeed, difficult to explain the phenomenon, which seems to persist among vastly different ideologies and political movements. The racist Nazis had a mystical vision of the Jews as poisoners of Western purity and civilization while the egalitarian communists saw them as "ideological immigrants." The Jews don't have a monopoly in suffering others' bigotry, but they may be the most experienced at it. Why? The Jewish people is uniquely strange. They are defined at once through biology - one is Jewish merely by being born of a Jewish mother, regardless of belief - and ideology - one joins the people by adopting a specific faith. They call themselves a slew of disconnected words, from "culture" and "faith" to "tribe" and "nation." A typical American Jew may believe his Jewish identity is a religious one while supporting passionately the Israeli project of a Jewish ethnic nation-state. An important Jewish leader could (though not without criticism) be a Buddhist, and one cannot stop being Jewish (according to Jewish law, at least) merely by choosing to become something else. To say they can be described but not defined is to ignore the fact that most Jews - those not engaged in modernity's "Who is a Jew?" controversies - do not feel Judaism is incoherent. They know what they are, but do not have the word - perhaps because it does not exist - for their idea-based (but not wholly ideological) ethnic identity. They are "Am Yisrael," the people of Israel, whatever that may be. Their identity, with all its confusions, is a product of ancient experience. The inner life, the Jewish bookshelf, which defines this people is vast and profound. Their strangeness is part and parcel of their inheritance. And so, in every generation, in almost every society in which they are a minority, the Jews are quintessentially and permanently different. Perhaps this is the reason that anti-Semitism has become what the Canadian jurist and MP Irwin Cotler has called "the canary in the coal mine of evil," always heralding a more pluralistic hatred. A nation's treatment of the Jews - a group that is not slightly different, but almost always deeply so - is the barometer of its capacity for accepting real difference. The Global Forum ended on Monday after two days of discussions and meetings that produced dramatic announcements for worldwide efforts to combat "the longest hatred." These included the establishment of an international coalition of activists, parliamentarians and NGOs to combat anti-Semitism worldwide - a coordinating force that has been markedly missing - and an association for scholars of anti-Semitism to be based at Yale University. These efforts are important and welcome, particularly when the world experiences a rise of street violence against Jews from Paris to Vladivostok which forces them to trade their kippot for baseball caps when walking down the street, and when government-sponsored anti-Semitic media and even official Holocaust denial are heard all too often in Teheran, Kiev, Caracas and in many Arab countries. But these initiatives are not likely to dramatically increase activism against or awareness of anti-Semitism in the near future. Announced in Israel at an event put on by the Jewish state's Foreign Ministry, they will generally be regarded, like most efforts to eradicate anti-Semitism, as Jewish efforts to deal with a Jewish problem. In that context, a "tentative" invitation issued at the summit of activists, scholars and parliamentarians is highly appropriate. British MP John Mann offered to have next year's Forum hosted in London. Such a move, received with approval by Israeli officials, could mark the beginning of a more international campaign. From London, a demand to the Kremlin to take Iran to task over its nuclear plans and Holocaust denial may resonate more widely. In London, the bitter experiences of one minority may be seen more readily as an international symbol for the oppression experienced by all minorities, and acted against with more alacrity. A world stage, in short, is the place to fight bigotry in all forms, starting with the oldest and most destructive of prejudices.