Watching the coverage of the Holocaust-denial convention of big liars in Tehran was an immersion in the theater of the surreal. All it lacked was Borat. Mahmoud Ahmadinejad, the bizarro president of Iran, had to be satisfied with David Duke.

On a short walk through Mitte, the neighborhood where I have been staying, I had to step over shiny bronze street plaques imbedded in the sidewalks of Rosenthaler Strasse to document the lives of Jewish men, women and children who lived there before the Nazis ripped them from their homes. These tiny plaques, placed throughout Berlin, mark the starting places for journeys that led to Auschwitz, Buchenwald and Dachau. The very sound of the names of the death chambers echoes a grisly cacophony of evil.

Few Berliners, or any other Germans, are at risk of believing the grotesque lies that emanated from the conference in Iran. Most of the world is grimly aware of what happened to 6 million Jews and 5 million others -- political prisoners, prisoners of war, homosexuals, gypsies and the halt and the lame whose blood couldn't conform to the standards of mental and physical purity demanded by the Nazis. Leaders of Western countries expressed the expected outrage at what went on in Tehran.

But it's not the West and the people of the 21st century that the conference was meant to persuade. The target audience, of course, was those who insist on living in the 12th century, whose bigotries need the sustenance of fresh lies about Israel and the Jews.

Hatred of Israel and the Jews is one of the most powerful tools the unreconstructed Arab and Muslim radicals use to maintain a unity of evil. Without Israel they would be forced to confront the splintering conflicts of clashing sects, external jealousies and economic competitiveness, and their leaders would be more vulnerable to opposition forces waiting to be unleashed against tyrannical governments. We got a glimpse of the shouted outrage of Iranian students on the day the conference opened: "Death to the dictator!" Only the word "chutzpah" captures the flavor of President Ahmadinejad's answer to the students: "Everyone should know that Ahmadinejad is prepared to be burned in the path of defending freedom and truth."

Jews are occasionally chided for perpetuating a "Holocaust industry" with their many books, movies, museums and memorials about the genocide, but conferences like the one in Tehran are a reminder of how easy it might be to rewrite history for nefarious purposes. Eli Wiesel warns that with the death of the remaining survivors, those who actually were eyewitnesses to the Holocaust, the anti-Semites always with us could more easily succeed in rewriting that history. It wouldn't be the first time.

Dan Diner, director of the Simon Dubnow Institute for Jewish History and Culture at the University of Leipzig, observes that different interpretations have already changed the collective Holocaust memory. "In years past," he writes in the Berlin daily Die Welt, "those Holocaust books which have achieved greatest popularity -- and which have chalked up almost sensational sales figures by the standards of historical works -- have tended to disregard hostility to Jews as the central ground for the destruction of European Jewry." These contemporary works, in their exploration of human motivation for perpetuating such evil, focus more on the issues of robbery and plunder, greed and economic calculation, and not anti-Semitism. It's easier to understand base emotions with a utilitarian purpose than to fathom the murder of people simply because of who they are.

Throughout history anti-Semitism has thrived from many perspectives, calculated to take advantage of political problems, but the bottom line reasoning always starts with Jew-hatred. Before the Third Reich, the Jews who converted to other religions could sometimes escape prejudice, but Hitler ordered the deaths of second- and even third-generation converts because their "blood" was contaminated.

Holocaust denial in the Middle East has other roots. The contemporary version goes back to the 1950s just after the state of Israel was born. Gamal Abdel Nasser, the Egyptian president who celebrated pan-Arab nationalism in the 1960s, said "no person, not even the most simple one, takes seriously the lie of the 6 million Jews who were killed." This big lie has been adopted by the Islamists who, in reality and not just in rhetoric, make no distinctions between Zionists and Jews. Their ultimate purpose is to act on Ahmadinejad's exhortation "to wipe Israel off the map."

In 1943, Heinrich Himmler warned that it was dangerous to speak publicly of the Nazi determination to exterminate the Jews. In 2001, Ahmadinejad is not so squeamish. Attention must be paid.