The Sturmabteilung (S.A., Storm Troopers), a grassroots organization, helped Hitler undermine the German democracy. The Gestapo (Geheime Staatspolizei, Secret State Police), a force recruited from professional police officers, was given complete freedom to arrest anyone after February 28. The Schutzstaffel (SS, Protection Squad) served as Hitler’s personal bodyguard and eventually controlled the concentration camps and the Gestapo. The Sicherheitsdienst des Reichsführers­SS (S.D., Security Service of the SS) functioned as the Nazis' intelligence service, uncovering enemies and keeping them under surveillance.

The Nazis attempted to quell increasing reports of the Final Solution by inviting the International Red Cross to visit Theresienstadt, a ghetto in Czechoslovakia containing prominent Jews. A Red Cross delegation toured Theresienstadt in July 1944 observing stores, banks, cafes, and classrooms which had been hastily spruced-up for their benefit. They also witnessed a delightful musical program put on by Jewish children. After the Red Cross departed, most of the ghetto inhabitants, including all of the children, were sent to be gassed and the model village was left to deteriorate.
The outbreak of war and the invasion of Poland brought a population of 3.5 million Polish Jews under the control of the Nazi and Soviet security forces,[14] and marked the start of a far more savage persecution, including mass killings.[6] In the German-occupied zone of Poland, Jews were forced into hundreds of makeshift ghettos, pending other arrangements.[15] Two years later, with the launch of Operation Barbarossa against the USSR in late June 1941, the German top echelon began to pursue Hitler's new anti-Semitic plan to eradicate, rather than expel, Jews.[16] Hitler's earlier ideas about forcible removal of Jews from the German-controlled territories in order to achieve Lebensraum were abandoned after the failure of the air campaign against Britain, initiating a naval blockade of Germany.[7] Reichsführer-SS Heinrich Himmler became the chief architect of a new plan, which came to be called The Final Solution to the Jewish Question.[17] On 31 July 1941, Reichsmarschall Hermann Göring wrote to Reinhard Heydrich (Himmler's deputy and chief of the RSHA),[18][19] instructing Heydrich to submit concrete proposals for the implementation of the new projected goal.[20]
While the Nazis murdered other national and ethnic groups, such as a number of Soviet prisoners of war, Polish intellectuals, and gypsies, only the Jews were marked for systematic and total annihilation. Jews were singled out for "Special Treatment" (Sonderbehandlung), which meant that Jewish men, women and children were to be methodically killed with poisonous gas. In the exacting records kept at the Auschwitz death camp, the cause of death of Jews who had been gassed was indicated by "SB," the first letters of the two words that form the German term for "Special Treatment."
The Nazis regarded the Slavs as subhuman, or Untermenschen.[426] In a secret memorandum dated 25 May 1940, Himmler stated that it was in German interests to foster divisions between the ethnic groups in the East. He wanted to restrict non-Germans in the conquered territories to schools that would only teach them how to write their own name, count up to 500, and obey Germans.[427][y] In November 1939 German planners called for "the complete destruction" of all Poles[430] and resettlement of the land by German colonists.[431] The Polish political leadership was the target of a campaign of murder (Intelligenzaktion and AB-Aktion).[432] Between 1.8 and 1.9 million non-Jewish Polish citizens perished at German hands during the course of the war; about four-fifths were ethnic Poles and the rest Ukrainians and Belarusians.[410] At least 200,000 died in concentration camps, around 146,000 in Auschwitz. Others died in massacres or in uprisings such as the Warsaw Uprising, where 120,000–200,000 were killed.[433] During the occupation, the Germans adopted a policy of restricting food and medical services, as well as degrading sanitation and public hygiene.[434] The death rate rose from 13 per 1000 before the war to 18 per 1000 during the war.[435] Around 6 million of World War II victims were Polish citizens; half the death toll were Jews.[436] Over the course of the war Poland lost 20 percent of its pre-war population.[436] Over 90 percent of the death toll came through non-military losses, through various deliberate actions by Germany and the Soviet Union.[433] Polish children were also kidnapped by Germans to be "Germanized", with perhaps as many as 200,000 children stolen from their families.[437]
Jews would be “utilised for work in the East… [The] sexes [will be] separated. Jews capable of work will be moved into these areas as they build roads, during which a large proportion will no doubt drop out through natural reduction. The remnant that eventually remains will require suitable treatment…The evacuated Jews will first be taken, group by group, to so-called transit ghettos, in order to be transported further east from there.”
According to the Quad City Times, Yanina Cywinska was a 10-year-old student at the Kirov Ballet in Leningrad (now St. Petersburg) when her Polish Catholic parents suddenly called her home to Warsaw. Cywinska's parents, a physician and an artist, worked to assist Jews imprisoned in the Warsaw ghetto during the Nazi occupation of Poland until they themselves were placed in a Warsaw detention center. Once the family boarded trains for Auschwitz, Yanina would never see her parents or brother again.
The next year, 1942, marked the beginning of mass murder on a scale unprecedented in all of human history. In January, fifteen top Nazis led by Reinhard Heydrich, second in command of the SS, convened the Wannsee Conference in Berlin to coordinate plans for the Final Solution. The Jews of Europe would now be rounded up and deported into occupied Poland where new extermination centers were being constructed at Belzec, Sobibor, Treblinka, and Auschwitz-Birkenau.

This past fall, I reached out to Hana Amir, Zeidel’s daughter, and we spoke several times over Skype. From her home in Tel Aviv, Amir, who is slight and spectacled, with a gray bob, told me about how she learned of her father’s story. When Amir was young, Zeidel worked as a truck driver, and he was gone for long stretches at a time. At home, he was withholding with his daughter and two sons. “My father was of a generation that didn’t talk about their emotions, didn’t talk about how they felt about what they’d been through,” Amir told me. “This was their coping mechanism: If you’re so busy with moving forward, you can disconnect from your memories.” But there were signs that the past wasn’t done with Zeidel: Amir believes he suffered from recurrent nightmares, and he was fastidious about his personal hygiene—he washed his hands many times a day.

In 1935, Mengele earned a PhD in anthropology from the University of Munich.[7] In January 1937, he joined the Institute for Hereditary Biology and Racial Hygiene in Frankfurt, where he worked for Dr. Otmar Freiherr von Verschuer, a German geneticist with a particular interest in researching twins.[7] As von Verschuer's assistant, Mengele focused on the genetic factors that result in a cleft lip and palate, or a cleft chin.[10] His thesis on the subject earned him a cum laude doctorate in medicine (MD) from the University of Frankfurt in 1938.[11] (Both of his degrees were revoked by the issuing universities in the 1960s.)[12] In a letter of recommendation, von Verschuer praised Mengele's reliability and his ability to verbally present complex material in a clear manner.[13] The American author Robert Jay Lifton notes that Mengele's published works were in keeping with the scientific mainstream of the time, and would probably have been viewed as valid scientific efforts even outside Nazi Germany.[13]