—“Can a country lose its cultural heritage if the country borrows from other cultures, which become a part of their culture as well?”—

We have all borrowed from one another for all of history. And those isolated areas that could not borrow from others not only didn’t improve, but in many cases (New Zealand, Australia) regressed. (I am still studying the empires of west Africa and it’s possibly been a problem there also.)

However, borrowing isn’t always voluntary, and borrowing isn’t always good. Islam has been a destructive force everywhere it’s been adopted – although to different degrees, judaism (membership), christianity (resistance), islam (rule) were spread by coercion rather than choice.

So we can import good things (metallurgy, engineering, farming practices), or we can import bad things (lower trust, political competition, underclasses) or we can import really bad things (means of deception, means of propagandizing, means of coercion, means of rule).