decisive mainland battle; final battle on the home islands
Historical term referring to the anticipated land battle on the Japanese mainland in the final stage of World War II.
In preparation for the decisive mainland battle, civilians were made to train with bamboo spears.
We learned about the plans for the final battle on the home islands in history class.
Compound of 本土 (mainland, home country) and 決戦 (decisive battle). The term is historically associated with World War II.