The Imperial Japanese military song Nihon Rikugun (日本陸軍) begins with the line "天に代わりて不義を討つ" ("defeat injustice in place of righteousness").
What exactly did they consider 不義/fugi in Imperial Japan? Did it simply refer to opposing ideologies? Or is there a greater context distinct from the modern sense of "injustice" (especially considering that Imperial Japanese actions are considered unjust today).