The dramatic rise in antisemitism across the length and breadth of Europe is more than unsettling for the Jewish community. But it should also be of deep concern to European governments, which have watched as extremist parties and organizations have seized the public stage to vent their rage over the past several years.Much of this is taking place in Eastern Europe, but it is not only there that these practitioners of hate are mobilizing. From Ireland in the west to the eastern reaches of the continent, and from both the Left and the Right, rallies, posts on Facebook and other social media, and acts of violence are targeting Jewish communities, their institutions and individuals in a way not seen since the end of World War II.The beating of an eight-year-old boy wearing a kippa in Paris last week was only the latest example of this alarming trend. Two months ago, tens of thousands of people rallied in Warsaw, chanting the Nazi slogan “Sieg Heil” and “Ku Klux Klan.” Banners touting racist slogans such as “Pure Blood” and “White Europe” revealed the grassroots animus that has long served as the foundation for antisemitism in Poland and elsewhere in Europe. Such street demonstrations and similar language were staples in the cities of Central and Eastern Europe in the 1930s, and are now returning.Political parties, such as Golden Dawn in Greece, Jobbik in Hungary, Ataka in Bulgaria and the National Front in France traffic in the same xenophobic rhetoric. That in some countries the Jewish population is relatively small has nothing to do with the vehemence of those who engage in such behavior. Indeed, the expression “antisemitism without Jews” emerged from state-sponsored antisemitism in Eastern Europe 50 years ago.While growing antisemitism and bigotry of the far Right is deeply troubling, the role that being anti-Israel plays in the political Left also cannot be overstated. Antisemitic motifs underline much of the extreme Left’s likening Israel to the Nazis, to apartheid South Africa, and its charges that the Jewish state is “racist” and committing genocide against the Palestinians.Editorial cartoons, posters at demonstrations and social media messages often cast Israelis in images that could have appeared in Der Sturmer.Adding fuel to this fire are attacks against the Jewish religion. Already four countries in Europe have banned shechita, or kosher slaughter. During a debate over the issue in Norway, one legislator said that if the Jews were disturbed by the ban, “Let them go somewhere else.” Similar efforts to ban circumcision are also occurring in a number of countries. IN THE MIDST of all this, on January 29, the Italian government hosted the Rome Conference on the Responsibility of States, Institutions and Individuals in the Fight Against Antisemitism in the Organization for Security and Cooperation in Europe. Italy is the new chair of the OSCE, an organization composed of 57 member countries and 11 partner countries, dedicated to common security and human rights issues. Co-sponsoring the meeting were the Office for Democratic Institutions and Human Rights – which is the OSCE’s human rights arm, the Center for Contemporary Jewish Documentation in Milan and the Union of Italian Jewish Communities.The conference also coincided with the 80th anniversary of Italy’s racial laws, promulgated by its Fascist government on the eve of World War II.There has been a series of such conferences aimed at combating antisemitism, sponsored by the organization over the past 15 years. The key word in the conference’s concept paper is “responsibility.” The gathering in Rome – of more than 400 diplomats, human rights NGOs, Jewish leaders and others – heard presentations on the role and responsibility of lawmakers and civil servants, the challenge of hatred on digital platforms, and the role of educators, sports and religion in addressing the growing virus of hate directed against Jews in Europe.The statements each country represented at the meeting, delivered at the plenary session, were also important. Having to go on the record to report what individual governments are doing to assess antisemitism within their borders and how they are acting to respond, is not just an exercise in blowing diplomatic hot air. Granted, some presentations were perfunctory, but others demonstrated an appreciation that the world is watching, and that left unchecked, the 1930s will return in the 21st century, aided by the Internet and social media platforms.THIS YEAR, Italy will also chair the International Holocaust Remembrance Alliance, a consortium of countries that offer primarily Holocaust education programs in schools and related remembrance activities. Membership in this group is not automatic; a country has to be elected based on fulfilling certain standards.In 2016, the IHRA adopted a working definition of antisemitism. It is important that the OSCE adopt similar language to educate public officials, journalists, teachers and others about contemporary manifestations of antisemitism.Conferences of this type often set high expectations – for the moment – many of which we find go unfulfilled. One objective has been met by the convening of the meeting itself. Certainly one cannot conceive of a gathering like this taking place in the 1930s.Had it, a spotlight would have shone on the evil and barbarity about to grip the Jews of Europe in its clutches. Even 40 or 50 years ago, such a meeting would be unlikely, since the Soviet Union and its satellites in Eastern Europe would never own up to their own brand of antisemitism, which targeted Jewish religious observance and any kind of activity or connection to Zionism and to Israel. So the fact that more than 50 countries met to deliberate on the subject is, as we say, a “dayenu moment” – meaning, if we only have this, it is sufficiently important.But, of course, that isn’t enough. Once again, the shadows of hatred loom over Jewish communities, some of whose elderly members still wear tattoos on their arms to attest to what happens when societal “responsibility” – by governments, the media and individuals – fails to materialize when it is needed most.The Rome Conference has laid down the challenge and the imperative to act.Will the countries of Europe see the need to seize the imperative? Or will the easier path of looking the other way cause Europe to fail its Jews twice within memory? Daniel S. Mariaschin is the executive vice president and CEO of B’nai B’rith International. As the organization’s top executive officer, Mariaschin directs and supervises B’nai B’rith programs, activities and staff around the world.