> That is like claiming there should be no global Internet or no global trade.
There is no such thing as a global internet. The internet is just a bunch of separate networks. Of course this being "hacker news" you wouldn't know what the internet is.
There is no such thing as global trade. There are a bunch of trade relations between regions and countries.
> People like to interact with one another, for various reasons: business, science, mere curiosity.
People like to interact with their own for the most part.
> Having the globe split into several mutually non-communicating regions would be weird,
Where did I say this? It's amazing how people are so stupid that they think you need english for people to communicate with each other. Do you think japanese and chinese people didn't communicate each other before english? Or russians and germans without english?
> And in absence of hard barriers in North Korean style, one dominant way of communication is likely to emerge.
No. The historical norm is major regional languages. Not one dominant language enforced on the world primarily through military supremacy.