The Doolittle Raid was military insignificant, and in no way should have altered Japan's belief that their home islands were geographically unassailable. Even

The Doolittle Raid was military insignificant, and in no way should have altered Japan's belief that their home islands were geographically unassailable. Even in 1945, with the Imperial Japanese Navy suppressed or destroyed and their supply chain in tatters, an invasion would have been incredibly costly. Occupying enemy territory, across an ocean, with a large population of civilians disinclined to cooperate, is never easy.