Countries/sovereigns controlling your entry to THEIR borders is not new.
Your home country controlling your entry to OTHER countries is what’s relatively (~100 years old) new.
#freedomofmovement #passport
Discussion
Applied through the passport system.
You can only get your passport from your country(ies) of citizenship, with few exceptions.
If you’re a single-citizen, your ability to make lawful bordered entries to other countries is subject to a single point of failure - your own country.