Kimmel could prepare an ambush by moving the fleet out of Pearl Harbor during the night of 6-7 December. Dispersing air defences, keeping radar operating, and going to full alert would also reduce the damage of a Japanese strike. Many of those measures belonged to the Army's chain of command, so Kimmel could not simply order every part of Hawaii's defence. Reconnaissance from two cruiser captains and their supporting destroyer force would give the Army strong reason to act. The expected cooperation rested on the local commanders' workable relationship and the credibility of the warning.
Notable Point · 48:48-50:19
How Kimmel could secure Army and Navy readiness in Hawaii
A credible sighting would let Kimmel prepare the fleet and press for Army defensive measures despite their separate chains of command.