防備 ぼうび都市 とし宣言 せんげんだったら
mubōbito shi sengendattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 無防備都市宣言

1. If it were a declaration of an undefended city.; If it was declared an undefended city.

Tara Conditional