At the time the movie that this speech was given at the end of, some of the largest corporations in the U.S. were supplying Hitler with any and everything he wished to wage war with. Henry Ford had supplied trucks for the North African operations and had been supplying Hitler with $50,000 a year for quite awhile... Hitler had anti semitic books on tables outside of his office that he had anyone that visited him take a copy of to read. The Ethyl corporation supplied the octane booster of the same name for the use in aircraft and American Oil was shipping fuel by the tanker loads. Prescott Bush's father in law was a major financier of the Nazi cause and G.M. subsidiary Adam Opel built the engines for the first jet aircrafts that were used by the Luftwaffe against Allied forces and G.M. was repaid for damages by bombing of the subsidiary at the end of the war. Davis oil company was smuggling mercury out of Mexico off of both the Atlantic and Pacific coast to the Japanese and Germans to use in the primers in small arm bullet primers. That is some of what I recall off of the top of my head after a long tiring day but there is much much more incidents of allies supporting the Nazi cause not just at the beginning but throughout the war. The speech given by Charlie Chaplin at the end of "The Great Dictator" was used to justify Hoover to label him as a Communist and his campaign for a second front in European theater of war made him also a target of McCarthy at the wars end with Chaplin being denied reentry into the U.S. after a trip to Europe in 1952.

Speech from 'The Great Dictator' (1940)