Worldwide, he said, anti-Semitism is as rife today as at any time since World War II. An Anti-Defamation League survey last year of attitudes in 102 countries found that one in four people held classic stereotypes, believing Jews control finance and media and were more loyal to Israel than to their home countries. In many Middle Eastern and North African nations, the proportion of such attitudes was over 80 percent. Half of the 53,100 adults surveyed had never heard of the Holocaust. And since 2000, he said there had been an increase in violence against Jews, noting that in recent weeks a Jewish teenager with a skullcap was beaten in France.

“I did not think in my lifetime, the Jewish communities of Europe would struggle with the question of whether they have a future there,” said Mr. Foxman, who is 75. “People said to me anti-Semitism is finished. But it’s no longer history. It’s current.”

While American attitudes have shifted significantly — only 1 in 10 hold anti-Semitic views compared to 1 in 3 when Mr. Foxman joined the league in the mid-1960s — on some college campuses students feel intimidated if they disagree with a popular view that Israel is the villain in the Palestinian conflict, he said. At University of California, Los Angeles and Stanford, Jewish students applying for judicial and student government positions were asked whether their Judaism would allow them to objectively weigh pro-Palestinian activists or the movement to boycott Israeli products.

Still, he said, “I don’t think it’s an epidemic.”

The Anti-Defamation League has been Mr. Foxman’s career. He joined it in 1965 as a fresh law school graduate and became national director in 1987. Then, it was one of several organizations whose views might be sought on controversies involving Jews or Israel. Today, it is often the first.

“He led from his kishkes,” said Gary Rosenblatt, editor and publisher of The Jewish Week newspaper, using the Yiddish word for guts. “He is very smart, deeply identified as a Jew. He’s emotional and has authenticity.”