Two movie I will include for ambiance are: 55 Days at Peking and Khartoum; both star Charlton Heston and both play to the deep seated fear of native uprisings.
One theme in the Pulps, and why I no longer recommend friends read the actual material, is a fevered dream of the ‘last white man on Earth’, and the causal racism which drives it. It’s a paranoid counterpoint to the colonial vision of the the ‘white man’s burden’.
Both ERB and REH wrote stories of savage apocalypses, which is part of the ratified world of Pulps.
After the Great War xenophobia was on the rise. Henry Ford, Walt Disney, and Charles Lindbergh were well known anti-Semites, and less well known racists.