पर्वतान्तर्द्वीपाश्च दुर्गा नाध्युष्यन्ते जनपदाभावात् ॥ कZ_०८.१.३१ ॥
parvatāntardvīpāśca durgā nādhyuṣyante janapadābhāvāt
山岳の城塞と島の城塞は、支えとなる地方(ジャナパダ)がなければ、持続的に居住・維持されない。
Geography alone does not secure defense; a fort must be fed, staffed, and financed by a productive and connected hinterland.