They were talking about citizens there, not random people from other countries.

Nowhere in the definition of a free country does it state that you have to be a citizen.

Even in the US constitution that is not the case. Unalienable rights extend to everyone under the constitutions jurisdiction, which includes people who are not citizens. Even aliens get due process in the US. Or should, anyway, if we didn't have anti-American leadership.

When defining a Constitution for a country, to whom would you direct the constitutional precepts? Surely it would only be for people that were to be governed by the constitutional government. China, for example, would not cover American citizens in their Constitution.

The US constitution explicitly covers people who are not US citizens. It's not up for interpretation, you're just wrong.