Preparing Pearl Harbor while Japan fires first

One branch lets Washington preserve the political value of a Japanese first shot without leaving Pearl Harbor helpless. Kimmel could recall Enterprise and send Lexington out with additional aircraft for the returning carrier, then concentrate their task groups. The battle fleet could slip out during the night before the attack while personnel ashore took shelter. American carrier aircraft could follow the returning Japanese strike and attack its carriers during recovery, with dispersed land-based aircraft adding to the attack. Flight decks occupied by landing or launching aircraft would offer a particularly vulnerable moment. Roosevelt would still be unlikely to accept the risk to American lives merely to secure an unambiguous cause for war.