Four decision branches after the Kido Butai is found

The first branch lets Kimmel prepare an ambush while Washington says nothing; the second has Japan continue after an American disclosure. A third branch ends the immediate crisis through withdrawal and tense diplomacy. The fourth uses indirect imperial action to replace Tojo, opening a possibility of internal conflict or a new government without assuming that Hirohito opposed Japanese expansion generally. Nagumo and Yamamoto could recall the force before the political leaders settled their response, while Kimmel could prepare his fleet without deciding whether the United States would declare war.