Anything from several hundred thousand to 1.5 million Armenians are estimated by historians to have been killed by Muslim Ottoman Turks between 1915 and 1923, in what is widely viewed as one of the first modern instances of systematic genocide. Turkey, however, denies that the episode should be regarded as genocide, arguing that the death toll has been greatly exaggerated and that the deaths occurred in the context of civil war and unrest. The dispute has erupted afresh in recent days and weeks, in part because of controversy within the Anti-Defamation League over how to address the issue. The ADL has recently recognized the massacre as "tantamount to genocide," and reinstated a regional director who had been fired for opposing its previous reluctance to do so. While Israel is acutely and understandably sensitive to its relationship with the current Turkish government, a key ally, the Jewish state, which rightly protests Holocaust denial wherever it occurs, cannot possibly be complicit in the denial of genocide elsewhere. To that end, Yad Vashem, Israel's official Holocaust memorial, has always included the massacre of the Armenians in its educational activities on "other instances of genocide, ethnic cleansing and mass murder." Similar stances have always been taken by other organizations dedicated to Holocaust education, such as the Simon Wiesenthal Center. Dating back to its first museum in 1979, the Wiesenthal Center has taken pains to include presentational material relating to the Armenian Genocide. How could it be otherwise? The Jewish nation, the overwhelming victim of the Nazi Holocaust, is centrally committed to learning and promulgating the lessons of the Holocaust - to highlighting man's capacity for inhumanity toward his fellow man and to seeking to curb it, stressing the dangers in order to prevent recurrences of genocide. Unthinkably, genocide has recurred, and continues to recur, because such lessons are not sufficiently internalized. "Never again" has been exposed as an empty mantra, most recently in Rwanda and Darfur. The open, good-conscience examination by affected nations of dark episodes in their history is a key element in trying to change that dire reality. Israel is scarcely in a position to force Turkey to confront its dark episode, but neither can Israel signal any acquiescence in overlooking it. To denounce the Armenian Genocide is not to denounce Turkey and its current government; it did not perpetrate these killings. But its responsibilities are those of a successor government, and must not be ducked. Our global tragedy is that what the former Canadian justice minister Irwin Cotler has described as a "genocide in the making" is being perpetrated, right now, in Darfur, in an era of globalized communication where no nation can claim to be unaware of what is unfolding. And the next potential tragedy is developing before our eyes as well, similarly unobstructed by the international community. President Mahmoud Ahmadinejad and the Iranian regime openly call for Israel's destruction and are seeking the means to achieve it - in open breach of the UN's post-World War II "Never Again" convention. Yet the Iranian president, far from being indicted by the global body established precisely to counter such outrages, is instead afforded a platform by it, and his country is allowed to retain its membership in the family of civilized nations even as it threatens the very existence of another sovereign member. To quote comments made by Cotler to this newspaper several months ago: "Ahmadinejad's genocidal criminality is as clear and compelling as any I've ever seen... This is advocacy of the most horrific of crimes, genocide; embedded in the most virulent of hatreds, anti-Semitism; propelled by a publicly avowed intent to acquire nuclear weapons for that purpose; and dramatized by the parading in the streets of Teheran of Shihab-3 missiles draped in the emblem 'Wipe Israel Off the Map.'" What is required in facing down those who would commit genocide, of course, is an alliance of all enlightened nations, taking concerted action to thwart such ambitions long before they are implemented. Striving for a better future, however, also requires acknowledging and internalizing the crimes of the past.