Respuesta :
Well, this answer is hugely personal, but I'd argue it's due to the US's law against international intervention (it took the Japanese attack on Pearl Harbour to finally convince the congress to join the war) and the fact that fascist ideas were pretty popular in the south of the country, namely in the regions that were sympathetic to racial segregation with whom the idea of a superior race promoted by fascist and nazi ideology was pretty popular. Again, this is based on my opinion, I am no pre-WW2-American scholar!
Answer:
Britain, France, and the United States were not willing to risk war for high principle if validating that principle imperiled vital interests. None of the countries had an active interest in whether or not Japan controlled Manchuria. If the United States denied joining the League, nations would have no idea how to object in case Germany walked out. Hitler’s military occupation of the Rhineland was a direct challenge to France. Yet, the USA did not act militarily since France, with its huge army, did not do that in its interests (Buchanan).