だい日本 にっぽん帝国 ていこく陸軍 りくぐんであれば
dainipponteikokuri kugundeareba

Noun
Da Copula

The "-eba" conditional form ("if/when…") of 大日本帝国陸軍

1. If it were the Great Japanese Imperial Army; Were it the Great Japanese Imperial Army

Ba Conditional