The US believed in isolation, if another country attacked the US that is the only way that we would get involved, therefore we tried to stay out of the mass killings and havoc that the Germans and Japanese were creating until we felt that it involved the US. The US did not want to pick a side and have to stay loyal to that side and go to war when that country did because of the alliance. The US finally joined in to help the allied powers to supply them with weapons/military troops. They did not enter the war until December 1941.
