There are all sorts of stories about how Hull's underlings ran away from advance warnings about the attack including a very credible warning from the Swedish ambassador.
Whatever the case, Hull kept the Japanese ambassador waiting outside the office until the attack actually took place. Had the warning been received and relayed in a timely manner, it is probably that at least some of the lives lost at Pearl Harbor would have been spared.
And FDR would still have had his war with the American public being only slightly less angry about an attack which took place within the hour or two after the declaration of war versus a pure sneak attack.
Yup Cordell was a snake in oh so many ways