Different cultures have distinct methods of separating one another, at least in theory and language if not in (political) practice.
"Ayyan Mani's thick black hair was combed sideways and parted by a careless broken line like the borders the British used to draw between two hostile neighbors" says Manu Joseph (says, not writes: I intentionally omitted a comma: from first lines of "Serious Men" ; NY ; 2010)
We even separate sentences with things like commas, although some writers demur. Sometimes.
Sets of rules and patterns order the world. Capitalistically advanced, developed nations, going by the patterns of the U. S, England, and France, when not trying to spy on one anothers' underpants, seem quite free to trade (free-to-free-trade). But, labor is not free to travel --- i.e. between countries, and this reveals that capitalism has a secret need to separate. An African man has to get on an escalator, in order to get make use of the system. Capitalism is hybrid because it restricts access and grants access --- at the same time.
Yes, it is hybrid: as it lies sometimes, tells truth sometimes. Truth and lies exist together here in a queer context, one that is also ideological.
Language is ambiguous, too, just like capitalism. The borders of truth are ambiguous when expressed in the language of discourse, clear enough when expressed in territory and the language of law. The result is a set of rules. Societies everywhere have their own sets of rules for the a universal purpose --- their social organization. Also in order to separate, that is to say, from one another.
When two such nations have different ideas on how to do that, I guess prbably these differences may "meet at the border."