Yes, God did create Nations, (nationalities) but pretty sure it was men who created borders...?
It is such a conundrum because I so feel for these people.
There's a good book on the subject..... it's all about borders. It's called "the Bible." You should read it-- it's wonderful.
In it, you'll read over and over where God defined borders.... saying things like this-- to Abraham>>>>
Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates. (aka-- from border to border)