All the aircraft carriers were sent out to sea east of the island, out of harms way.
FDR knew.
Of course anyone who was anyone knew. The US had broken the codes and delayed the Japanese ambassadors meeting to discuss a declaration of war between Japan and the US until after the attack. There is hardly a time this country has gone to war that the reasons were manufactured or misrepresented. Remember the Maine, The Lusitania, Pearl Harbor, 9/11, Egypt, Libya and Serbia. Of course don’t forget Vietnam.