The Blitzkrieg was fundamentally about moving away from the tried and tested methods of modern warfare and creating a new, more effective doctrine. To that end, Hitler had given his full backing to Guderian. Ironically, he had got his idea for Blitzkrieg from two officers – one from France and one from Britain and he had copied and broadened what they had put on paper. In Britain and France, however, the cavalry regiments ruled supreme and they were adamant that the tanks would not get any influence in their armies. The High Commands of both countries were dominated by the old traditional cavalry regiments and their political pull was great. These were the type of officers despised by Hitler and he took to his Panzer officer, Guderian, over the old officers that were in the German Army (the Wehrmacht). 
^ After the invasion of Poland, the Germans planned to set up a Jewish reservation in southeast Poland around the transit camp in Nisko, but the "Nisko Plan" failed, in part because it was opposed by Hans Frank, the new Governor-General of the General Government territory.[147][148][149] Adolf Eichmann was assigned to remove Jews from Germany, Austria, and the Protectorate of Bohemia and Moravia to the reservation.[150] Although the idea was to remove 80,000 Jews, Eichmann had managed to send only 4,700 by March 1940, and the plan was abandoned in April.[151] By mid-October the idea of a Jewish reservation had been revived by Heinrich Himmler, because of the influx of Germanic settlers into the Warthegau.[152] Resettlement continued until January 1941 under Odilo Globocnik,[153] and included both Jews and Poles.[154] By that time 95,000 Jews were already concentrated in the area,[155] but the plan to deport up to 600,000 additional Jews to the Lublin reservation failed for logistical and political reasons.[156]
December 11, 1941 - Hitler declares war on the United States. President Roosevelt then asks Congress for a declaration of war on Germany saying, "Never before has there been a greater challenge to life, liberty and civilization." The U.S.A. then enters the war in Europe and will concentrate nearly 90 percent of its military resources to defeat Hitler.

With the financial backing of several Jewish investors, including one of the owners, Abraham Bankier, Schindler signed an informal lease agreement on the factory on 13 November 1939 and formalised the arrangement on 15 January 1940.[b] He renamed it Deutsche Emailwarenfabrik (German Enamelware Factory) or DEF, and it soon became known by the nickname "Emalia".[25][26] He initially acquired a staff of seven Jewish workers (including Abraham Bankier, who helped him manage the company[27]) and 250 non-Jewish Poles.[28] At its peak in 1944, the business employed around 1,750 workers, a thousand of whom were Jews.[29] Schindler also helped run Schlomo Wiener Ltd, a wholesale outfit that sold his enamelware, and was leaseholder of Prokosziner Glashütte, a glass factory.[30]

"For the survivor who chooses to testify, it is clear: his duty is to bear witness for the dead and the living. He has no right to deprive future generations of a past that belongs to our collective memory. To forget would be not only dangerous but offensive; to forget the dead would be akin to killing them a second time. The witness has forced himself to testify. For the youth of today, for the children who will be born tomorrow. He does not want his past to become their future." Elie Wiesel, Night, Preface to the New Translation (New York: Hill and Wang, c2006), page xv.

Tested by the Germans during the Spanish Civil War in 1938 and against Poland in 1939, the blitzkrieg proved to be a formidable combination of land and air action. Germany’s success with the tactic at the beginning of World War II hinged largely on the fact that it was the only country that had effectively linked its combined forces with radio communications. The use of mobility, shock, and locally concentrated firepower in a skillfully coordinated attack paralyzed an adversary’s capacity to organize defenses, rather than attempting to physically overcome them, and then exploited that paralysis by penetrating to the adversary’s rear areas and disrupting its whole system of communications and administration. The tactics, as employed by the Germans, consisted of a splitting thrust on a narrow front by combat groups using tanks, dive bombers, and motorized artillery to disrupt the main enemy battle position at the Schwerpunkt. Wide sweeps by armoured vehicles followed, establishing the Kessel that trapped and immobilized enemy forces. Those tactics were remarkably economical of both lives and matériel, primarily for the attackers but also, because of the speed and short duration of the campaign, among the victims.
Timothy D. Snyder (Bloodlands: Europe Between Hitler and Stalin, 2010): "In this book the term Holocaust signifies the final version of the Final Solution, the German policy to eliminate the Jews of Europe by murdering them. Although Hitler certainly wished to remove the Jews from Europe in a Final Solution earlier, the Holocaust on this definition begins in summer 1941, with the shooting of Jewish women and children in the occupied Soviet Union. The term Holocaust is sometimes used in two other ways: to mean all German killing policies during the war, or to mean all oppression of Jews by the Nazi regime. In this book, Holocaust means the murder of the Jews in Europe, as carried out by the Germans by guns and gas between 1941 and 1945."[23]
Prior to the German offensive in May, Winston Churchill had said "Thank God for the French Army".[89] That same French army collapsed after barely two months of fighting. This was in shocking contrast to the four years of trench warfare they had engaged in during the First World War. The French president of the Ministerial Council, Reynaud, attributed the collapse in a speech on 21 May 1940:
Raphael Lemkin, a holocaust survivor who worked on the Nuremberg Trials, coined the term genocide and spent 4 years pushing for it to be added to international law. As Champetier de Ribes, the French Prosecutor at the Nuremberg Trials explained “This [was] a crime so monstrous, so undreamt of in history throughout the Christian era up to the birth of Hitlerism that the term ‘genocide’ has had to be coined to define it.” Ultimately, in 1948 The United Nations Convention on the Prevention and Punishment of Genocide was adopted, and it entered into force in 1951. The convention defined genocide in legal terms based on Lemkin’s work, and is the basis for genocide prevention efforts today.
Following the invasion of Poland, German occupation policy especially targeted the Jews but also brutalized non-Jewish Poles. In pursuit of lebensraum, Germany sought systematically to destroy Polish society and nationhood. The Nazis killed Polish priests and politicians, decimated the Polish leadership, and kidnapped the children of the Polish elite, who were raised as “voluntary Aryans” by their new German “parents.” Many Poles were also forced to perform hard labour on survival diets, were deprived of property and uprooted, and were interned in concentration camps.

In less than 24 hours I shall be departing with my wife and two friends for a holiday in Krakow. As a minority of one I have been outvoted on whether we should visit Auschwitz Berkenau. Very reluctantly I will go. As an ex soldier, I am hardly a shrinking violet and perhaps more aware than some of the horrors of war or even lesser conflicts. I don't need to pore over such things. But many seem to cherish a ghoulish and prurient interest in such places. They are right to remember what happened there. From such knowledge mankind just might avoid or prevent anything similar happening again...but I doubt it. Look around the world. Horrors have existed, still exist and almost certainly will happen again. The scale is not the most significant factor. One child or adult butchered with machettes, bombs or bullets or bombs or tortured to death is just as horrific. Somehow I already feel guilty for allowing myself to go. For me it is almost on a par with digging up a coffin just to observe the putrefying remains of some departed soul. Why do some feel compelled to do that...does it awake in some a compassion that they did not previously have? No number of visits to such places can possibly make anyone feel and suffer as the inmates undoubtedly did. It takes some considerable effort to understand how a post-Auschwitz society can promote and run profiteering bus tours to one of the closest places humanity has to Hell. History cannot be changed by tears. Perhaps it is a forlorn hope but we would all do well to remember such places and events and then move forwards, using our best efforts to stop the slaughters that are occurring right now. That is where our consciences and efforts are most needed.

His grip on German society tightened and those who publicly objected to Nazi policies were often sentenced to hard labour in the rapidly expanding concentration camp system. Jews were subjected to further laws restricting their rights, but rising anti-Semitism in Europe wasn’t limited to Germany. In the UK, Oswald Mosley’s British Union of Fascists gained support from sections of the public and press, even filling the Royal Albert Hall in April.

The Auschwitz Birkenau camp complex comprises 155 brick and wooden structures (57 in Auschwitz and 98 in Birkenau) and about 300 ruins. There are also ruins of gas chambers and crematoria in Birkenau, which were dynamited in January 1945. The overall length of fencing supported by concrete poles is more than 13 km. Individual structures of high historical significance, such as railway sidings and ramps, food stores and industrial buildings, are dispersed in the immediate setting of the property. These structures, along with traces in the landscape, remain poignant testimonies to this tragic history.
In the aftermath of the Holocaust, many of the survivors found shelter in displaced persons  camps administered by the Allied powers. Between 1948 and 1951, almost 700,000 Jews emigrated to Israel, including 136,000 Jewish displaced persons from Europe. Other Jewish displaced persons emigrated to the United States and other nations. The last camp for Jewish displaced persons closed in 1957.
During the era of the Holocaust, German authorities also targeted other groups because of their perceived racial and biological inferiority: Roma (Gypsies), people with disabilities, and some of the Slavic peoples (Poles, Russians, and others). Other groups were persecuted on political, ideological, and behavioral grounds, among them Communists, Socialists, Jehovah's Witnesses, and homosexuals.
As in the concentration camps, those prisoners selected for work faced appalling conditions and severe treatment. After being woken at dawn, they would have to stand in line for the roll call and endure many hours of hard labour. At the end of the working day, exhausted, they returned to the camp, when they would once again have to stand in line for evening roll call.
His middle-class Catholic family belonged to the German-speaking community in the Sudetenland. The young Schindler, who attended German grammar school and studied engineering, was expected to follow in the footsteps of his father and  take charge of the family farm-machinery plant. Some of Schindler’s schoolmates and childhood neighbors were Jews, but with none of them did he develop an intimate or lasting friendship. Like most of the German-speaking youths of the Sudetenland, he subscribed to Konrad Henlein’s Sudeten German Party, which strongly supported the Nazi Germany and actively strove for the dismemberment of Czechoslovakia and their annexation to Germany . When the Sudetenland was incorporated into Nazi Germany in 1938, Schindler became a formal member of the Nazi party.
Oskar Schindler (28 April 1908 – 9 October 1974) was a German industrialist and a member of the Nazi Party who is credited with saving the lives of 1,200 Jews during the Holocaust by employing them in his enamelware and ammunitions factories in occupied Poland and the Protectorate of Bohemia and Moravia. He is the subject of the 1982 novel Schindler's Ark and its 1993 film adaptation, Schindler's List, which reflected his life as an opportunist initially motivated by profit, who came to show extraordinary initiative, tenacity, courage, and dedication to save the lives of his Jewish employees.