दुर्गादीनि च कर्माणि प्रभूत्येन क्रियन्ते ॥ कZ_०७.११.०८ ॥
durgādīni ca karmāṇi prabhūtyena kriyante
Fortification and related state works are carried out through abundance (of resources).
A surplus base—adequate revenue, materials, and supplies—because fortification is capital-intensive and long-term.
Secure and grow the resource base first; major defense works follow from sustained surplus, not from ad hoc extraction.