Anarcho capitalists definitely do believe in borders.
There’s virtually nothing libertarian about the federal government. You think libertarians are responsible for globalism?? LOL! Neither libertarians nor paleos nor constitutionalists support managed trade agreements. It would actually be the political left (including GOP) which is for globalism.
I think you have your definitions mixed up. Badly.
I’ve had Libertarians tell me borders are stupid and they hate defense spending. Many of them.