I recently returned from participating in the largest ever Inter-Parliamentary delegation to mark International Remembrance Day at Auschwitz, and to commemorate also the 69th anniversary of the liberation of the most brutal extermination camp of the 20th century.

For me, as for my fellow Jewish and non-Jewish Parliamentarians, it was a uniquely moving and painful moment – of bearing witness to horrors too terrible to be believed, but not too terrible to have happened.

From 1942 to 1944, 1.3 million people were murdered at Auschwitz – of whom 1.1 million were Jews – recalling Elie Wiesel’s dictum that, “The Holocaust was a war against the Jews in which not all victims were Jews, but all Jews were victims.”

As I reflect now on my recent visit to the Valley of Death, there are a number of lessons that bear recall and reminder.

The first is the importance of zachor, of remembrance. As we remembered the victims of the Shoah – defamed, demonized and dehumanized as prologue and justification for genocide – Holocaust survivors who were with us reminded us that the mass murder of six million Jews, and millions of non-Jews, is not a matter of abstract statistics. As we say at such moments of remembrance, “Unto each person there is a name, each person has an identity, each person is a universe” – the whole emphasized in our reciting of the Kaddish, the prayer for the dead, at various moments of bearing witness – the most painful being the spontaneous recital of the Kaddish upon exiting the barracks containing the crematoria. Here again Holocaust survivors reminded us that “whoever saves a single life it is as if he or she has saved an entire universe.” Thus, the abiding imperative: we are each, wherever we are, the guarantors of each other’s destiny.

The second enduring lesson is that the genocide of European Jewry succeeded not only because of the industry of death – of which the crematoria are a cruel reminder – but because of the Nazis’ state-sanctioned ideology of hate. Indeed, the screenings in Block 27 of the Auschwitz-Birkenau barracks, say it all. As early as 1924, Adolf Hitler wrote, “No one need be surprised if among our people, the personification of the devil as the symbol of all evil assumes the living shape of the Jew.” Again and again, in these screenings, the Jew was depicted as the incarnation of evil, as the enemy of humanity, as the parasite among the nations, as the destroyer of cultures. Simply put, the Jew devil is the enemy of humankind, and humanity can only be redeemed by the death of the Jew.

As the Canadian Supreme Court affirmed, “the Holocaust did not begin in the gas chambers – it began with words.” This finding has been echoed by the international criminal tribunals in Rwanda and the former Yugoslavia. The importance of this lesson is underscored by the incitement to hate and genocide that continues to emanate from the Iranian regime.

The third lesson is the danger of anti-Semitism – the oldest and most enduring of hatreds – and the most lethal. If the Holocaust is a metaphor for radical evil, anti-Semitism is a metaphor for radical hatred. Let there be no mistake about it: Jews died at Auschwitz because of anti-Semitism, but anti-Semitism did not die. And as we have learned only too painfully, while anti-Semitism begins with Jews, it doesn’t end with Jews.

The fourth painful and poignant lesson – and one particularly relevant for us as Parliamentarians – is that these Holocaust crimes resulted not only from state-sanctioned incitement to hatred and genocide, but from crimes of indifference, from conspiracies of silence – from the international community as bystander.

As it happens, this International Holocaust Remembrance Day occurred on the eve of the 20th anniversary of the Rwandan genocide, when from April to July 1994, close to one million Rwandans were murdered. What makes the Rwandan genocide so unspeakable is not only the horror of the genocide itself, but that this genocide was preventable.

No one can say that we did not know; we knew, but we did not act.

Today, we know but have yet to act to stop the slaughter of civilians in Syria, ignoring the lessons of history and mocking the Responsibility to Protect doctrine.

Let there be no mistake about it: Indifference and inaction always mean coming down on the side of the victimizer, never the victim. In the face of evil, indifference is acquiescence.

The fifth lesson is that the Holocaust was made possible not only because of the “bureaucratization of genocide,” as Robert Lifton put it and as the desk-murderer Adolf Eichman personified, but because of the trahison des clercs – the complicity of the elites – including physicians, church leaders, judges, lawyers, engineers, architects and educators.

Holocaust crimes, then, were also the crimes of the Nuremberg elites.

It is our responsibility, then, to speak truth to power, to hold power accountable to truth, and to ensure that the double entendre of Nuremberg – of the Nuremberg Laws that enshrined racism as well as the Nuremberg Principles that laid the groundwork for prosecuting war crimes – are part of our learning and our legacy.

The sixth lesson concerns the vulnerability of the powerless and the powerlessness of the vulnerable, as dramatized at Auschwitz by the remnants of shoes, suitcases, crutches, and hair of the murdered, and as found expression in the triad of Nazi racial hygiene: the Sterilization Laws, the Nuremberg Race Laws, and the Euthanasia Program – all of which targeted those “whose lives were not worth living.”

It is revealing, as Prof. Henry Friedlander points out in his work titled “The Origins of Nazi Genocide,” that the first group targeted for killing were the Jewish disabled.

It is our responsibility, then, as parliamentarians and citizens of the world, to give voice to the voiceless and to empower the powerless, be they the disabled, poor, elderly, women victimized by violence, or vulnerable children – the most vulnerable of the vulnerable.

Seventh is the tribute that must be paid to the rescuers, the righteous among the nations, of whom Raoul Wallenberg is metaphor and message. Wallenberg, a Swedish non-Jew, saved more Jews in six months in Hungary in 1944 than almost any single government or organization. Tragically, the man who saved so many was not himself saved by so many who could have.

Eighth, and a refrain heard in the closing get-together of Parliamentarians, it is not the case that if there had been no Holocaust there would not have been a State of Israel. It is the other way around – and we should never forget it – that if there had been a State of Israel there might well not have been a Holocaust or the horrors of Jewish and human history.

Finally, as this visit reaffirmed, we must remember – and celebrate – the survivors of the Holocaust, the true heroes of humanity. For they witnessed and endured the worst of inhumanity, but somehow found, in the depths of their own humanity, the courage to go on, to rebuild their lives as they helped build our communities.

And so, together with them we must remember – and pledge – that never again will we be indifferent to incitement and hate; never again will we be silent in the face of evil; never again will we indulge racism and anti-Semitism; never again will we ignore the plight of the vulnerable; and never again will we be indifferent in the face of mass atrocity and impunity.

We will speak up – and act – against racism, against hate, against anti-Semitism, against mass atrocity, against injustice – and against the crime of crimes whose name we should shudder to mention: genocide.

Irwin Cotler represented the Canadian parliament and the International Parliamentary Coalition to Combat Anti-Semitism as part of the Inter-Parliamentary delegation to Auschwitz. He is a Canadian Member of Parliament, and a former Canadian Minister of Justice and Attorney-General, and an emeritus Professor of Law at McGill University.