Eldians are forced to live in stagnation and humility (versailles treaty) because they lost a war when their king betrayed them (back stab myth)

The eldians used to rule large parts of the world for thousands of years (return to past greatness)

These two parts also apply directly to Japan. The Japanese Empire, its fall from grace, and being trapped on a small island. You can read the story as a story about how the Japanese should forge out of their island and re-stake their rightful claim to the world, which is entirely against them and keeping them trapped there.