Many Jews attempted to flee Germany, and thousands succeeded by immigrating to such countries as Belgium, Czechoslovakia, England, France and Holland. It was much more difficult to get out of Europe. Jews encountered stiff immigration quotas in most of the world's countries. Even if they obtained the necessary documents, they often had to wait months or years before leaving. Many families out of desperation sent their children first.
Perhaps the main area of dispute about this process concerns Hitler’s precise role in ordering the killing of the Jews. Remarkably, we simply do not know, in an unequivocal way, what Hitler’s precise role was. The dictator often gave oral orders to senior henchmen such as Heinrich Himmler that were never written down, and historians can only infer Hitler’s precise role and intentions from evidence which is infuriatingly inadequate and contradictory. Because of the lack of unambiguous evidence, historians have been divided for decades, rather misleadingly, into so-called “intentionalists,” who argue that Hitler always intended to kill the Jews, and “functionalists,” who claim that the killing process somehow, as it were, welled up from local SS units in Russia until it became general Nazi policy.

In October 1939 Hitler signed a "euthanasia decree" backdated to 1 September 1939 that authorized Reichsleiter Philipp Bouhler, the chief of Hitler's Chancellery, and Karl Brandt, Hitler's personal physician, to carry out a program of involuntary "euthanasia"; after the war this program was named Aktion T4.[98] It was named after Tiergartenstraße 4, the address of a villa in the Berlin borough of Tiergarten, where the various organizations involved were headquartered.[99] T4 was mainly directed at adults, but the "euthanasia" of children was also carried out.[100] Between 1939 and 1941, 80,000 to 100,000 mentally ill adults in institutions were killed, as were 5,000 children and 1,000 Jews, also in institutions. In addition there were specialized killing centres, where the deaths were estimated at 20,000, according to Georg Renno, the deputy director of Schloss Hartheim, one of the "euthanasia" centers, or 400,000, according to Frank Zeireis, the commandant of the Mauthausen concentration camp.[101] Overall, the number of mentally and physically handicapped murdered was about 150,000.[102]

Similarly, in Ordinary Men (1992), Christopher Browning examined the deeds of German Reserve Police Battalion 101 of the Ordnungspolizei ("order police"), used to commit massacres and round-ups of Jews, as well as mass deportations to the death camps. The members of the battalion were middle-aged men of working-class background from Hamburg, who were too old for regular military duty. They were given no special training. During the murder of 1,500 Jews from Józefów in Poland, their commander allowed them to opt out of direct participation. Fewer than 12 men out of a battalion of 500 did so. Influenced by the Milgram experiment on obedience, Browning argued that the men killed out of peer pressure, not bloodlust.[471]

Historians disagree as to when and how the Nazi leadership decided that the European Jews should be exterminated. The controversy is commonly described as the functionalism versus intentionalism debate which began in the 1960s, and subsided thirty years later. In the 1990s, the attention of mainstream historians moved away from the question of top executive orders triggering the Holocaust, and focused on factors which were overlooked earlier, such as personal initiative and ingenuity of countless functionaries in charge of the killing fields. No written evidence of Hitler ordering the Final Solution has ever been found to serve as a "smoking gun", and therefore, this one particular question remains unanswered.[105]

…selected by the camp doctor, Josef Mengele, for medical experiments. Auschwitz doctors tested methods of sterilization on the prisoners, using massive doses of radiation, uterine injections, and other barbaric procedures. Experiments involving the killing of twins, upon whom autopsies were performed, were meant to provide information that would supposedly lead…
In the 1960s, Otto Frank recalled his feelings when reading the diary for the first time, "For me, it was a revelation. There, was revealed a completely different Anne to the child that I had lost. I had no idea of the depths of her thoughts and feelings."[23] Michael Berenbaum, former director of the United States Holocaust Memorial Museum, wrote, "Precocious in style and insight, it traces her emotional growth amid adversity. In it, she wrote, 'In spite of everything, I still believe that people are really good at heart.'"[23]
In May, Nazis under the direction of SS Lt. Colonel Adolf Eichmann boldly began a mass deportation of the last major surviving population of European Jews. From May 15 to July 9, over 430,000 Hungarian Jews were deported to Auschwitz. During this time, Auschwitz recorded its highest-ever daily number of persons killed and cremated at just over 9000. Six huge open pits were used to burn the bodies, as the number of dead exceeded the capacity of the crematories.

Unlike Belzec, Sobibor, Treblinka, and Lublin-Majdanek,[96] which were built in the occupied General Government territory inhabited by the largest concentrations of Jews,[97] the killing centre at Auschwitz subcamp of Birkenau operated in Polish areas annexed by Nazi Germany directly. The new gas chambers at Bunker I were finished around March 1942 when the Final Solution was officially launched at Belzec. Until mid-June 20,000 Silesian Jews were killed there using Zyklon B. In July 1942, Bunker II became operational. In August, another 10,000–13,000 Polish Jews from Silesia perished,[98] along with 16,000 French Jews declared 'stateless',[99] and 7,700 Jews from Slovakia.[98]
Freund and I walked the path of the tunnel, over the large hummock of earth, out toward the surrounding pines. Not such a long distance on foot, perhaps, but positively heroic when one considered that it had been dug, night after night, by chained men who had spent their daylight hours laboring at their unthinkable task, subsisting on nothing more than gruel.
After crossing the Soviet demarcation line in 1941, what had been regarded as exceptional in the Greater Germanic Reich became a normal way of operating in the east. The crucial taboo against the killing of women and children was breached not only in Białystok, but also in Gargždai in late June.[38] By July, significant numbers of women and children were being killed behind all front-lines not only by the Germans, but also by the local Ukrainian and Lithuanian auxiliary forces.[39] On 29 July 1941, at a meeting of SS officers in Vileyka (Polish Wilejka, now Belarus), the Einsatzgruppen had been given a dressing-down for their low execution figures. Heydrich himself issued an order to include the Jewish women and children in all subsequent shooting operations.[40] Accordingly, by the end of July the entire Jewish population of Vileyka, men, women and children were murdered.[40] Around 12 August, no less than two-thirds of the Jews shot in Surazh were women and children of all ages.[40] In late August 1941 the Einsatzgruppen murdered 23,600 Jews in the Kamianets-Podilskyi massacre.[41] A month later, the largest mass shooting of Soviet Jews took place on 29–30 September in the ravine of Babi Yar, near Kiev, where more than 33,000 Jewish people of all ages were systematically machine-gunned.[42] In mid-October 1941, HSSPF South, under the command of Friedrich Jeckeln, had reported the indiscriminate killing of more than 100,000 people.[43]
In early 1942 the Nazis built killing centres at Treblinka, Sobibor, and Belzec in occupied Poland. The death camps were to be the essential instrument of the “final solution.” The Einsatzgruppen had traveled to kill their victims. With the killing centres, the process was reversed. The victims were taken by train, often in cattle cars, to their killers. The extermination camps became factories producing corpses, effectively and efficiently, at minimal physical and psychological cost to German personnel. Assisted by Ukrainian and Latvian collaborators and prisoners of war, a few Germans could kill tens of thousands of prisoners each month. At Chelmno, the first of the extermination camps, the Nazis used mobile gas vans. Elsewhere they built permanent gas chambers linked to the crematoria where bodies were burned. Carbon monoxide was the gas of choice at most camps. Zyklon-B, an especially lethal killing agent, was employed primarily at Auschwitz and later at Majdanek.
The Nazis then combined their racial theories with the evolutionary theories of Charles Darwin to justify their treatment of the Jews. The Germans, as the strongest and fittest, were destined to rule, while the weak and racially adulterated Jews were doomed to extinction. Hitler began to restrict the Jews with legislation and terror, which entailed burning books written by Jews, removing Jews from their professions and public schools, confiscating their businesses and property and excluding them from public events. The most infamous of the anti-Jewish legislation were the Nuremberg Laws, enacted on September 15, 1935. They formed the legal basis for the Jews' exclusion from German society and the progressively restrictive Jewish policies of the Germans.
The Nazi concentration camps were established beginning in 1933 for the purpose of imprisoning political opponents. After the “Night of the Long Knives” (see Chapter 8, page 65), authority and management of the concentration camps was turned over to the S.S. The S.S. expanded the concentration camp system, and used these facilities to warehouse other “undesirables,” including hundreds of thousands of Jews. Dachau, Buchenwald and Sachsenhausen were among the first concentration camps built by the Nazis near Munich, Weimar, and Berlin respectively.

The “real contents” had already been altered by Frank himself, and understandably, given the propriety of his own background and of the times. The diary contained, here and there, intimate adolescent musings, talk of how contraceptives work, and explicit anatomical description: “In the upper part, between the outer labia, there’s a fold of skin that, on second thought, looks like a kind of blister. That’s the clitoris. Then come the inner labia . . .” All this Frank edited out. He also omitted passages recording his daughter’s angry resistance to the nervous fussiness of her mother (“the most rotten person in the world”). Undoubtedly he better understood Edith Frank’s protective tremors, and was unwilling to perpetuate a negative portrait. Beyond this, he deleted numerous expressions of religious faith, a direct reference to Yom Kippur, terrified reports of Germans seizing Jews in Amsterdam. It was prudence, prudishness, and perhaps his own deracinated temperament that stimulated many of these tamperings. In 1991, eleven years after Frank’s death, a “definitive edition” of the diary restored everything he had expurgated. But the image of Anne Frank as merry innocent and steadfast idealist—an image the play vividly promoted—was by then ineradicable.

Most of the book is about the privations and hardship of living hidden away in the "annex". There is very little coverage of the violence of the times or much that is going on in the outside world because they had little knowledge of it since they were hidden. I think this is partly why some schoolchildren report the diary is boring. It does get repetitive at times, which reflects the feelings of those living in hiding. They had to wait and wait in fear, not knowing what the next day would bring.
Some ghettos were initially open, which meant that Jews could leave the area during the daytime but had to be back by a curfew. Later, all ghettos became closed, meaning that Jews were not allowed to leave under any circumstances. Major ghettos were located in the cities of Polish cities of Bialystok, Lodz, and Warsaw. Other ghettos were found in present-day Minsk, Belarus; Riga, Latvia; and Vilna, Lithuania. The largest ghetto was in Warsaw. At its peak in March 1941, some 445,000 were crammed into an area just 1.3 square miles in size.

Mengele sailed to Argentina in July 1949, assisted by a network of former SS members. He initially lived in and around Buenos Aires, then fled to Paraguay in 1959 and Brazil in 1960, while being sought by West Germany, Israel, and Nazi hunters such as Simon Wiesenthal who wanted to bring him to trial. He eluded capture in spite of extradition requests by the West German government and clandestine operations by the Israeli intelligence agency Mossad. He drowned in 1979 after suffering a stroke while swimming off the Brazilian coast, and was buried under a false name. His remains were disinterred and positively identified by forensic examination in 1985.