Or, the presumption of a monolithic morality, ethics, societal order, code of behavior, humanity, etc
It is this presumption of sameness that accounts for about 95% of the ills currently inflicted upon the world. And it is leading to increasing conflict and agitation.
Even within, say, the continental United States there is rural America and urban America; and never the twain shall meet. They are two different societies with different moral and ethical codes of conduct and behavior (let alone customs).
Then you have racial, ethnic, religious and regional societies within the US that have no more in common than Japan has with Syria.
Granted, all empires try to impose (to one degree or another) their system upon all and sundry.
But it’s also true that all empires come to tragic and messy ends. Creeds do not a center make.
Still, it’s worth keeping in mind, even on a personal level, that not everyone thinks like you, feels like you, sees the world the way you do or wants a world that you want.