How about starting with something like "The Constitution is not a suicide pact"? It's certainly a serious argument for a strong, in this domain, serious centra

How about starting with something like "The Constitution is not a suicide pact"? It's certainly a serious argument for a strong, in this domain, serious central government. I don't think anything in federalism besides the usual political stuff applies. And that "usual political stuff" is where this government gets it moral legitimacy, which partly addresses your point, especially when we strip away ludicrous hyperbole like "world-ending" (maybe your world would end, but things would remain largely unchanged for perhaps half the world's population, and not severely changed for a very large fraction of the rest; the world is big, and we are small). And while "might makes right" might not settle well with your moral tastes, operationally, might rules. Otherwise, you might be counting yourself lucky to be speaking Russian. But not needing to speak Punic.