The news of the death of Robert Wistrich on May 19 leaves his colleagues and friends in Israel and around the world stunned and deeply saddened. On the basis of an astonishing record of scholarly productivity since the 1970s, he had been for some time the world’s leading historian of modern anti-Semitism. As Director of the Vidal Sassoon International Center for the Study of Anti-Semitism at Hebrew University, he organized multiple lectures and conferences that brought scholars to Israel and supported critical research on the topic—research that might not have found funding elsewhere. Wistrich was an indispensable cyclone of scholarly energy and intellectual creativity and a much valued colleague. His death is a huge loss to the international historical profession, to Hebrew University and also to the broader political and intellectual world that is focused on anti-Semitism in world politics today. Fittingly, just before his death he had gone to Rome, where he was scheduled to speak to members of the Italian Senate about the rise of anti-Semitism in Europe in recent years.

He was as much at home in the quiet of a scholar’s study as in the public political forum, where his eloquence and insight drew the attention of heads of state and leading politicians. He leaves a large and rich scholarly legacy. In works such as Anti-Semitism, The Longest Hatred (1992), Hitler and the Holocaust (2001), and Laboratory for World Destruction and Germans and Jews in Central Europe (2007), he explored the familiar, traditional, Christian, secular forms and generally right-wing extremist forms of Jew-hatred. They remain and will remain important works for anyone interested in understanding what we have called in recent years “the old anti-Semitism,” namely the forms of Jew-hatred that contributed to the Holocaust of European Jewry.

Yet as valuable as those books were, a major aspect of Robert Wistrich’s distinctive scholarly contribution consists in his focus on two other sources of the longest hatred. The first was the antagonism to Jews and to Israel coming from the Soviet Union and the Communist states and parties as well as from the Western radical left, both before and after the founding of the State of Israel. The second was anti-Semitism in the Middle East and Iran, expressed both in secular Arab nationalism as well as in religiously inspired Islamist radicalism. In both instances, he explored the relationship between hatred of the Jews as Jews and antagonism to Zionism and then to the state of Israel. Wistrich was a subtle thinker. He understood that not all criticism of Israel was due to anti-Semitism. Yet he also documented the many similarities between the conspiratorial theories that had been applied to Jews in Europe and those that were being applied to the supposed vast power of the Jewish state. He viewed such attacks as Jew-hatred posing in the guise of anti-Zionism.

Robert Wistrich’s preoccupation with antagonism to the Jews that came from the traditions of the European left was longstanding and evident in the titles of his books on the subject: Revolutionary Jews from Marx to Trotsky (1976), The Left against Zion (1979), Socialism and the Jews (1982), and From Ambivalence to Betrayal: The Left, the Jews and Israel (2012). While writing about the anti-Semitism of the Nazis was standard fare in the international historical profession, Wistrich’s focus on anti-Semitism of the radical left was not received with equal enthusiasm by a profession more comfortable with a focus on the sins of the Nazis than of the Communists and their fellow travelers. When it was not fashionable to do so, he drew attention to the anti-Semitism that lurked in the slogans of the Communist and leftist anti-Zionism of the Cold War era. His books and articles on that subject will remain standard works for many years to come.

In A Lethal Obsession: Anti-Semitism from Antiquity to the Global Jihad (2010), he offered a vast compendium of what he called “the return of anti-Semitism.” (I reviewed the book in The New Republic.) The book was an examination of a new and important chapter the history of anti-Semitism, one focused on attacks on Zionism and Israel. Its language was a mélange of themes of the old anti-Semitism of the European far right with a mix of secular leftist and Islamist ideologies. Where the rallying cry of the old anti-Semitism was the attack on “world Jewry,” the core of the lethal obsession with the Jews had now become the assault on “international Zionism” and the state of Israel. There had been what Wistrich importantly called a shift in the geographical center of gravity of anti-Semitism from Europe to the Middle East and Iran. Significant as it was, this was a shift too much of the political and scholarly mainstream failed to acknowledge.

In A Lethal Obsession, Wistrich wrote:

These pages expose the intensity of the “culture of hatred” that currently permeates books, magazines, newspapers, sermons, videocassettes, the Internet, television, and radio in the Middle East on a scale unprecedented since the heyday of Nazi Germany. Indeed, the demonic images of Jews presently circulating in much of the Islamic world are sufficiently radical in tone and content to constitute a new warrant for genocide. They combine to devastating effect the blood libel of medieval Christian Europe with Nazi conspiracy theories about the Jewish drive for world domination and dehumanizing Islamic quotations about Jews as the ‘sons of apes and donkeys.

He argued that this was a bigotry that “cannot be adequately understood in terms of the Arab-Israeli conflict alone or the so-called question of Palestine.” Rather, “the mythical thinking that animates Islamist ideology is much closer to the Nazi model, with its fixation on destroying a secret Jewish power that strives for global hegemony.” Much of the anti-Semitic worldview that had been expressed by the “totalitarian atheists” of the Nazi regime had infected the body politic of Islam during the past forty years. Its focus has become “the collective Jew” embodied in the state of Israel. Its geographic center has moved to the Middle East, but the tone and content of the rhetoric, along with the manifest will to exterminate the Jews, are virtually identical to German Nazism. The leadership of Iran does not even disguise its desire for a judenfrei (Jew-free) Middle East—a “world without Zionism,” to adopt a more politically correct language. Radical Islamists of every stripe openly proclaim at every opportunity that the eradication of Israel is a divine commandment, the will of God, and a necessary prologue to the liberation of mankind. In a manner reminiscent of the Nazis, they see themselves as engaged in a war of civilizations against terminal Western decadence…

These deeply unsettling conclusions rested on a sound foundation of careful empirical research and interpretation. In the era of euphemism in the United States and in Europe, far too many political leaders still refuse to speak frankly about the evidence that Wistrich and other scholars have gathered in abundance.

Tragically, Robert Wistrich’s terribly premature death has deprived us of the voice of the foremost scholar of the return of anti-Semitism in our times. Through many years of painstaking yet passionate scholarship, he has left us a large body of work to read, ponder and discuss as we attempt to understand anti-Semitism’s past, present, and sad to say, its future. Wistrich, like all great scholars, sought to find and present the truth as best he could, even when that truth was unsettling and disturbing. We honor his memory best by paying close attention to what he wrote and to the warnings he voiced.