Batman and Robin were Nationalists. Behold the truth, from Batman # 1:
Different era, different needs, but the same solution. Yeah, it was 1940, and "nationalism" may have meant something different to Americans enduring the pressure and propaganda of those who wanted America to enter World War II.
Given that, it's still interesting to see that one of the key principles of "Robin's Code" is "Nationalism," which today is routinely demonized as Literally Hitlerian.
But back then, it was okay to love your Nation. Today? You may only love the Globe.