The atrocities committed by Nazi soldiers during World War II are well known. I'd like to know what motivated those soldiers to do Hitler's bidding. Were they brainwashed? Did they believe they were doing the right thing in killing 6 million (Jewish) people? How could so many soldiers willingly and consistently execute thousands of defenseless and innocent people, including children, day after day?
I have to recommend the recent book Soldaten: On Fighting, Killing, and Dying by a historian and social psychologist here, as there isn't are more objective source for understanding the mindset of those German soldiers during WWII as their own conversations:
Let me quote some passages with author Neitzel in an BBC interview:
Both authors argue that Nazi soldiers were no more naturally violent than those anywhere else, but they did it in a very organized and systematic way. If you look at Chechnya war or some Wikileaks videos you see that obedience to orders even nowadays is the same dominant psychological pattern among soldiers and the "level" of brutality doesn't really differ qualitatively. The end justifies the means in war. Nearly everyone can become a mass murderer in war within few days.
Another article about the book states:
This got a bit long with mainly quotes, but it's a important and tricky question where any personal reasoning without facts would be highly unreliable to me.
The simple answer (and here I agree with @Evan Harper's comment) is deference to authority and careful planning by Nazis to hide the truth of what they were doing.
Deference To Authority
The most easily understood example of this it the Milgram exmperiment. This experiment was especially motivated by Holocaust trials. A summary from Milgram of the experiment read:
(65% of people committed what they believed was murder on the basis of authority, though they showed signs of stress and rebelliousness.)
The Holocaust was not really public information. For the majority of the Nazi Regime, Jews were mostly imprisoned in concentration camps. It was only in 1942 that extermination camps, where mass murders took place, were started. These extermination camps were not set up in Germany itself, but occupied Poland. Part of the reason was to hide the fact of the killings from the civil populace. Killing was mostly carried out by poison gas, which was considered to be psychologically acceptable to the soldiers operating the camp (besides being efficient). The holocaust was itself referred to the Holocaust as
The gas chambers were intentionally chosen to make it easy to kill lots of people. The Germans tried shooting gypsies and disabled people (the first victims) but their soldiers wouldn't be able to do it for long. It upset them. The Nazi party needed an easier way to kill lots of people.
The gas chamber was easy for their soldiers because one group of soldiers could escort the victims at the start when they were alive, and the victims would take off their clothes and get naked themselves, then they'd be killed, then another group of soldiers would only have to deal with dead bodies. There would not be soldiers who saw the killings, nor soldiers who saw the live people and then pressed the buttons. Since the victims were naked, the soldiers didn't have to remove clothes from the bodies. It was easy to keep the dead bodies out of sight.
I'm looking at "The Good Old Days" The Holocaust as Seen by Its Perpetrators and Bystanders, and at the Police Battalion studies, and I'm still thinking functionalism is more explanatory than intentionalism. Ordinary Germans, including the vast majority of the Wehrmacht, shared a racialist politics and during the circumstances of the war shared a common attitude towards resolving the racial problems of Jews and eastern and southern Slavs. Hitler's involvement was not decisive, as the rate of spontaneous massacre and the mixed class background of the Police Battalion soldiers demonstrates.
The historiography of the holocaust emphasises two causative accounts (both explained in depth at wikipedia with adequate citations there). The first is "intentionalism," this broadly focuses on Hitler's unique culpability for the decisions behind the holocaust, or limits these decisions to the inner circle of the NSDAP leadership or the Wehrmacht. Much of the US case at Nuremberg was intentionalist in its attitude to the causes of war crime.
Later scholarship evidenced the mass and widespread culpability of Wehrmacht soldiers, and in particular second line soldiers such at the soldiers of the Police Battalions. These soldiers were ordinary Germans. In the case of the Police Battalion studies, it was demonstrated that the class and occupational composition of these Battalions directly mirrored the class and occupational composition of Germany as a whole—they were representative males. In particular, they were older males who under the intentionalist schema of "brainwashed SS boys" should not have engaged in mass killings. But in the East, and in the West, and in the South—but, most particularly in the East and South (Soviet Union and Yugoslavia)—these ordinary men engaged quite willingly in voluntary Jew hunting and massacres of civilians. Evidence accumulated that Jew hunting and massacres were entirely voluntary, and that soldiers who showed no willingness to engage in massacres were allowed without punishment, scorn or humiliation to not engage in these activities. Jew hunting was discovered to be constructed as leisure by ordinary soldiers. This greatly strengthened the "functionalist" side of the argument, that the holocaust emerged out of functional requirements of the entire German war, that mass massacres and genocide were the ordinary business and outcome of war.
Genocide studies has furthered these findings. Current work in genocide studies engages the individual "massacre" as the unit of analysis, rather than the entire genocide. In part this is done because of the understanding developed from the German studies of the importance of ordinary participants and their attitudes.
While I primarily read genocide studies in the field of Soviet atrocities and attempts to analyse Soviet and Soviet-style atrocities as a singular whole, my understanding is that placing "Hitler" or "Nazism" as central to the holocaust is widely discredited; even where the unique contributions of Nazi ideology or organisational doctrine gave the holocaust distinctive colour. Historians rarely accept dichotomies without showing how they interpenetrate; but crude intentionalism is clearly discredited. Hitler was not directly responsible for the holocaust, except of course that he tolerated it, encouraged it, sought to order it, and perceived the German desire for it.
(Here you should consider reading about the history of Einsatzgruppen A in the Baltic states, its composition, and its eventual failure to achieve its stated aims due to psychological wear and tear. Einsatzgruppen A was comprised of NSDAP ideologues with higher University degrees, who believed in the racial purification of Germany and its mission of Empire in the East—and even they proved incapable of continuous intimate massacre despite their ardent beliefs in the NSDAP mission.)
Soldiers did not have to be motivated by or for Hitler to engage in atrocities. Atrocities were a historical part of the German method of waging war. (Even as they were part of the Japanese, or British, or Australian, or Soviet ways of waging war.) German soldiers voluntarily and with eagerness began implementing the basic program of the holocaust, and would have done so in the Soviet Union even without widespread official encouragement and support from directly NSDAP motivated and controlled organisations such as the Einsatzgruppern. In particular, the commissar order and anti-partisan operations were conducted with gusto and enjoyment. Germans also broadly agreed with the racial categories the NSDAP used, largely because the NSDAP's ideology was a mirror of German racialism.
German soldiers did not set out to kill six million Jews. They set out to punish Jews, Slavs and Communists as categories. The actual result of this was tens of millions of dead central and eastern europeans. Jews were especially singled out for special treatment in this schema, but the programme was the broad punishment including by collective death by massacre or starvation of Eastern and Southern Slavs generally, and specific cultural groups like Roma or Jews in particular. Even the formerly social democratic or communist German soldiers, such as in the police battalions, identified with the goal of punishing Jews and Slavs. Sometimes this punishment involved forced labour (conducted primarily as a form of ritualised humiliation with Jews, rather than for primarily economic gain). Sometimes this involved mass murder, industrial deportation of populations for a widely recognised final solution, or death marching prisoners with insufficient sources of food, clothing, shelter or medicine with a full awareness of the results.
Most current work points to the capture of large numbers of Soviet POWS in the transition from sporadic massacre to systematic attempts to destroy entire population groups, a "functionalist" analysis. POW camps for Soviet soldiers were run with a mentality of causing large scale deaths.
However, intentionalists can point to the NSDAP plans for the annihilation by starvation of all Jews and most Slavs West of the projected 1941 stop lines over the 1941-1942 winter. Indeed, the Wehrmacht's occupation planning attempted to implement just this. The targets of the holocaust, both in the minds of ordinary Germans, and in the planning of the NSDAP organs and organs that predated the NSDAP such as the junker dominated military synchronised in 1941. (Much of this comes out in Soviet evidence to Nuremberg which was always more functionalist).
Finally the question of how could soldiers willingly and consistently execute thousands of people day in day out? They couldn't. Einsatzgruppen A broke down under the psychological stress of mass executions, even using Baltic Hiwis to do the nasty work. Jew hunting and anti-partisan massacres were highlights, rewards, in the boring life of rear area policing. For front line units seconded to anti-partisan or clearance operations, they provided a welcome relief and a source of leisure in a far lower intensity environment.
The moral questions regarding personal culpability have for a long time focused on the blandness and ordinary nature of attempting to systematically annihilate civilian population groups. For current research I'd suggest starting with Chirot and McCauley (2006) Why Not Kill Them All?: The Logic and Prevention of Mass Political Murder.
Jews were (and in many placed in East Europe still are) very much hated by the population mostly because it is believed that they are guilty in killing Jesus Christ.
In Russian Empire for instance there were multiple bloody anti-Jewish pogroms. The only reason why the Jews were not killed by the non-Jewish population at the time was that the state mostly made efforts to protect the Jews or at least to limit the extent of hostilities.
When the state power was becoming weak, the scale of hostilities usually rose dramatically. For example during Russian civil war about 200000 Jews were killed even though no party of the conflict officially endorsed extermination of the Jews.
So once the state power completely changed their attitude from protecting the Jews or at worst, negligence to officially endorsing the killings and supporting that with additional propaganda efforts the effect was predictable.
The already anti-Semitic population that in most cases was willing to kill the Jews even despite the resistance of the state, was intentionally further indoctrinated against Jews and any remaining restrains lifted.
Adolf Hitler's goal in life was initially to become an artist. However, the Academy of Fine Arts Vienna denied Hitler's admission twice, in 1907 and 1908.
So, by the end of World War I, Hitler was strongly patriotic and anti-semitite. He stayed in the army after WWI and eventually was assigned to monitor the German Workers' Party (DAP). The DAP was strongly antisemitic, nationalistic, anti-capitalistic, and anti-Marxist. It favored a "strong active government, a 'non-Jewish' version of socialism, and solidarity among all members of society."
The president of the party, Anton Drexler was attracted to Hitler's oratory skills and invited Hitler to join, which he did. By 1921, Hitler had became known as a notorious speaker and became the leader of the DAP (which eventually came to be known as the Nazi party).
So as we see, Hitlers used his oratory skills to persuade the Germans to adopt his anti-sematic, anti-communist, totalitarian views. Hitler eventually rose to power and held grand rallies and made persuasive speeches with much Nazi Propaganda. Many Germans came to hold his views that Semitic and Romani races were inferior to Aryan races. Nazism openly declared Slavs as subhuman, however they slacked off on this idea somewhat when they became allies with Bulgaria, Croatia, and Slovakia.
Also, many Germans were still bitter of their loss of WWI. Their was a popular stab-in-the-back theory which Hitler supported. It claimed that Germany had never lost a war and that the German Army did not lose World War I, but was betrayed by the civilians and politicians on the home front. It has been stated that the stab-in-the-back theory was "an ideological cement of Hitler's dictatorship." The Germans were bitter at the the Allied powers, but mainly at the French who had occupied Germany during post-World War I. This pushed them to obey Hitler as he promised to repudiate the Treaty of Versailles. So this wasn't a case of brainwashing. There were two main factors at play here:
These two factors were supported by Hitler and formed the basis and ideology of Nazism. This motivated the many of the Germans to the bitter end.