Nazi policy did a great deal to facilitate denial of the Holocaust even as the killing operation unfolded across German-occupied Europe during World War II.

The Holocaust was a state secret in Nazi Germany. The Germans wrote down as little as possible. Most of the killing orders were verbal, particularly at the highest levels. Hitler's order to kill Jews was issued only on a need-to-know basis. The Nazi leaders generally avoided detailed planning of killing operations, preferring to proceed in a systematic but often improvised manner. The Germans destroyed most documentation that did exist before the end of the war. The documents that survived and related directly to the killing program were virtually all classified and stamped “Geheime Reichssache” (Top Secret), requiring special handling and destruction to prevent capture by the enemy. Heinrich Himmler, Reich Leader of the SS and Chief of the German Police, said in a secret speech to SS generals in Posen in 1943 that the mass murder of the European Jews was a secret, never to be recorded.

In order to hide the killing operation as much as possible from the uninitiated, Hitler ordered that the killings not be spoken of directly in German documentation or in public statements. Instead, the Germans used codenames and neutral-sounding terms for the killing process. In Nazi parlance, for example, “action” (Aktion) referred to a violent operation against Jewish (or other) civilians by German security forces; “resettlement to the East” (Umsiedlung nach dem Osten) referred to the forced deportation of Jewish civilians to killing centers in German-occupied Poland; and “special treatment” (Sonderbehandlung) meant killing.

Both at the time and later, such euphemisms impeded a clear understanding of what the Nazis were doing. This was partly to facilitate the killing process by keeping the victims in the dark about their fate as long as possible. Widespread Jewish resistance was only possible once Jews understood that Nazi policy was to kill all of them. Furthermore, Hitler could not just assume that almost no one would protest the killing of Jews. Even within his own party there were those who agreed with the campaign of persecution against Jews but who occasionally balked at systematic murder. For example, Wilhelm Kube, the German civilian administrator of occupied Belarus, fully supported the murder of the Belarusian Jews, but protested when the SS deported German Jews to Minsk and shot them there.

Hitler had reason to fear possible unfavorable reaction should all the details of the Holocaust become public. Euphemistic language aided secrecy since only those who knew the “real” meaning of the words would understand the deeper meaning of public statements or accurately interpret the documentary record.

In addition to the use of coded language, Heinrich Himmler sought to destroy the physical remains of the victims of killing operations to hide the killing process from advancing Allied armies. He assigned SS officer Paul Blobel to command Operation (Aktion) 1005, the code name for German plans to destroy the forensic evidence at mass murder sites. The SS forced prisoners to reopen mass graves at both the killing centers in German-occupied Poland and at the open air killing sites in the former Soviet territory and to cremate the bodies, thereby removing evidence of mass murder. For example, at Babi Yar in Kiev in the summer of 1943, at Belzec in late 1942, and at Sobibor and Treblinka in the fall of 1943, the mass graves were reopened and the bodies burned to ashes. In this way, the Germans and their collaborators destroyed much—but by no means all—of the forensic evidence of mass murder before advancing Soviet armies overran the scenes of these crimes.

A scene staged by the Nazis for the International Red Cross inspection of the Theresienstadt ghetto.Late in the war, after word of the Holocaust had reached Britain and the United States, the Nazi leadership sought to counter Allied condemnation of Nazi policies toward Jews with a coordinated campaign of disinformation. On June 23, 1944, the Nazis permitted an International Red Cross commission visit to the Theresienstadt ghetto in occupied Bohemia in what is today the Czech Republic. They hoped to mask Nazi killing operations in the occupied eastern territories by showcasing good conditions for Jews in Theresienstadt. The Red Cross commission consisted of two Danish officials and one Swiss representative and the visit lasted only six hours. It was an elaborate hoax. The SS authorities intensified deportations of Jews from the ghetto to alleviate overcrowding and spruced up the ghetto by planting gardens, painting houses, opening cafes and theaters and the like in preparation for the visit. They even instructed the prisoners how to behave during the inspection and to give positive reports about conditions in the ghetto. Once the visit ended, however, the SS authorities resumed deportations of Jews, overwhelmingly to the Auschwitz killing center in German-occupied Poland. The visit had served its purpose: to confuse international public opinion about the true nature of Nazi policies towards Jews.

Despite Nazi efforts to keep secret the unfolding Holocaust, information did leak out. The perpetrators themselves talked about what they were doing. Occasionally, survivors of mass killing operations bore witness to the killing program. Both Jewish and Polish underground organizations made great efforts to let the outside world know what the Germans were doing in eastern Europe. The information was sometimes incomplete, contradictory, and inaccurate in some of the specific details, but the general policy and pattern of events were clear by the second half of 1942.

Yet the psychological barriers to accepting the existence of the Nazi killing program were considerable. The Holocaust was unprecedented and irrational. It was inconceivable that an advanced industrial nation would mobilize its resources to kill millions of peaceful civilians, including women and children, the elderly, and the very young. In doing so, the Nazis often acted contrary to German economic and military interests. For example, they intensified the killing operation, killing skilled Jewish laborers even while labor shortages threatened to undermine the German war effort.

All too many people responded to reports about German killings of Jewish civilians by comparing these reports to news stories about German atrocities in occupied Belgium and northern France during World War I. The British media in World War I charged that the German occupation was monstrous, that German soldiers committed many outrages against defenseless civilians in German-occupied Belgium. They charged that German soldiers bayoneted babies, disfigured women, and killed civilians with military-issued poison gas. It turned out after the war that the Allies had invented many of those stories in order to maximize popular support for the war effort. As a result of that experience, many people were skeptical of reports of mass murder operations during World War II. In this case, however, the reports turned out to be generally accurate.

While some people today are misled as a result of the Nazi policies described above into doubting the reality of the Holocaust, others deny the Holocaust for more overtly racist, political, or strategic reasons. These deniers begin with the premise that the Holocaust did not happen. This premise suits their broader purposes. They deny the Holocaust as an article of faith and no amount of rational argumentation can dissuade them. This denial is irrational, largely unrelated either to the facts of the history or to the enormity of the event. Some people deny the Holocaust because of innate antisemitism, irrational hatred of Jews.

In fact, Holocaust denial has been called by some scholars the “new antisemitism” for it recycles many of the elements of pre-1945 antisemitism in a post-World War II context. Holocaust deniers argue that reports of the Holocaust are really part of a vast shadowy plot to make the white, western world feel guilty and to advance the interest of Jews. Even at the time of the Holocaust, some people in the United States thought reports of German massacres of Jewish civilians were actually propaganda reports designed to force the government to grant Jews special treatment and consideration.

Many people who deny the Holocaust argue that the supposed “hoax” served above all the interests of the State of Israel. Holocaust denial is, for these people, also an attack on the legitimacy of the State of Israel. Finally, others deny the Holocaust because they want to see a resurgence of Nazi racism. They insist that Nazism was a good political philosophy and that only “negative” press resulting from reports of the genocide the Nazis perpetrated prevent a revival of the Nazi movement today. They deny the Holocaust so that they can attract followers to a new Nazi movement.

Holocaust denial, then, unites a broad range of radical right-wing hate groups in the United States and elsewhere, ranging from Ku Klux Klan segregationists to skinheads seeking to revive Nazism to radical Muslim activists seeking to destroy Israel.

Holocaust deniers want to debate the very existence of the Holocaust as a historical event. They want above all to be seen as legitimate scholars arguing a historical point. They crave attention, a public platform to air what they refer to as “the other side of the issue.” Because legitimate scholars do not doubt that the Holocaust happened, such assertions play no role in historical debates. Although deniers insist that the idea of the Holocaust as myth is a reasonable topic of debate, it is clear, in light of the overwhelming weight of evidence that the Holocaust happened, that the debate the deniers put forward is more about antisemitism and hate politics than it is about history.