Part One: HISTORY
Just as American capital is presently invested in low-wage Asia while much of the U.S. work force is unemployed, during the Great Depression, the rich and powerful of America invested in low-wage, highly productive, and financially poor Nazi Germany.
While this writer's dad sold apples on the street corner, and with no money to buy milk, mom kept him breast fed past three years, workers in Nazi Germany were increasingly employed thanks to America's wealthy, who were fully aware of Hitler's intentions toward Jews and the Soviet Union.
U.S. and European financiers made possible prostrate Germany's rise to #1 military power while listening to Hitler's speeches trumpeting the historic expansionist call "Drang nach Osten' ("Push to the East') - that would bring about the smashing of the USSR so desired by investors frightened by Soviet successes, successes that were making the Russian revolution a model for the socialist activism arising everywhere.
Massive U.S. financial and industrial collaboration continued during the terrifying persecution of Jews, and to some extent through the giant investors' subsidiaries overseas even when the war in Europe was already underway.
Meanwhile, America, from top to bottom, was experiencing virulent anti-Jewish sentiment and discrimination that was in general hardly undiminished by abominable acts in Germany, like Kristallnach,t that were bringing unimaginable terror and suffering to Jews.
Over fifty of America's largest corporations or companies were operating inside Germany when it declared war on the United States - General Motors, General Electric, Ford, Du Pont, Rockefeller's Standard Oil and Chase Bank, I.T. & T, IBM, Kodak, Coca Cola, etc.. Throughout the war, the U.S. auto companies continued to be concerned Nazi Germany would nationalize American-owned factories. More than a few American companies were involved (some unknowingly) in the use of slave labor. After the war, General Motors and I.T. & T. received compensation for the damage done to their fighter plane and other military products factories in Germany by Allied bombing. 
Pro-Hitler and outspokenly anti-Jewish Joseph Kennedy and financial collaborator with Nazi banks, Prescott Bush, both punished by the Roosevelt administration, were planning the creation of their sons' presidential dynasties. While George Bush's maternal grandfather, founder of the banking and investment firm of G. H. Walker and Company, George Herbert 'Bert' Walker had handled American investments, Prescott Bush had specialized in British investors in Nazi Germany. 
Britain was America's closest ally. During the year 1936, the King of England and British Empire was for certain a greater follower of Hitler than most Germans. During the occupation of France, he, then the Duke of Windsor,  asked the German forces to place guards at his Paris and Riviera homes - and they did. His pro-Hitler statements, while Governor of the Bahamas during the war had to be hushed up. Even as late as 1970 he spoke affectionately of Hitler.
America's rich and famous partnered with Nazi bankers and industrialists for personal profit, many seeing fascism as favorable to their security as rulers of society. Many sought to withdraw from financial relations with Nazi enterprises because of the persecution of the Jews, others carried on with business through subsidiary companies even after America was in the war. A callous, merciless hands off policy was backed even when the Holocaust was well under way in preparation. This was certainly complicity and cooperation for the tight-lipped silence in high places. Enough news coverage had made everyone aware of what was being done to the Jews during most of the 1930s. 
At the end of the war, when ghastly, spine-chilling photos of the internment and murder of Jews in concentration camps were revealed, the public was shocked into some self-awareness. The most violent persecution, brutal arrests and internment had been done openly in a world basically owned and run by the "democratically' elected legislatures of white industrialized nations, nations that had earlier used their edge in arms manufacture to conquer, colonize and exploit the whole non white population of the world.