Giuliani spoke as chief US delegate to a 55-nation conference on fighting anti-Semitism. He pointed out the short distance to the Vienna square where adoring crowds mobbed Adolf Hitler as he celebrated the Anschluss, Nazi Germany's 1938 annexation of Austria. ''So many lessons of history have not been learned,'' Giuliani said. ''If action had been taken in the 1930s, then millions and millions of people would have lived.'' Anti-Semitism, he said, is ''a burden that has held Europe back for two millennia'' and is generated by the same hate that led to the attacks by Islamic terrorists on Washington and New York. Later, in a conference call with reporters, Giuliani said that Europe and the United States are working together to reduce attacks against Jews in a way that helps heal the divisions over the US-led war in Iraq. More than 350 delegates from Europe, central Asia, the United States, Russia, and Canada are attending the two-day conference, which was held amid an increase in anti-Semitic acts, especially in Europe. Giuliani said that US goals at the conference include agreeing on a uniform way to gather hate crime statistics and persuading all members of the Organization for Security and Cooperation in Europe, which is hosting the gathering, to adopt hate-crimes legislation. US officials also hope to persuade the OSCE to meet annually to discuss anti-Jewish prejudice and for all its members to begin educational programs about the issue. But no decision is likely before a meeting later this year of foreign ministers of the organization's member countries. The Simon Wiesenthal Center in Los Angeles, which tracks anti-Semitic incidents, said last month that attacks against Jews in Europe have reached the highest level since World War II. Since 2001, the center has documented 1,300 anti-Semitic acts in France, including the burning of a Marseille synagogue and the stabbing of a rabbi in Paris. In Britain, records show 1,308 attacks between 1998 and 2001.