Millions were upset at the results of WWI and the effect it had on society. The quick rise of modernity and industrialization was overwhelming to a quickly changing populace and unemployment was on the rise. Generally people wanted something different because it seemed like the world was on going crazy.
The main reason why America's ties with the Allies were stronger than the ties with the Central Powers was because of economic reasons. The Allies purchased large amounts of weapons and war goods from the United States. Germany was developing its own weapons thus it didn't enlist for American supplies.
The U.S was never prepared for the Pearl Harbor attack, the Japanese has everything planned out.
