6/ Moving on we have the case of Saint-Martin/Sint Maarten.
Saint-Martin is part of France . Sint Maarten
is a "constituent country" of the the Kingdom of the Netherlands
, as are Aruba
and Curaçao
in the Leeward Antilles.
https://en.wikipedia.org/wiki/Collectivity_of_Saint_Martin
https://en.wikipedia.org/wiki/Sint_Maarten