I am wondering which countries you can be headquartered in and have bases internationally?
US <=> Puerto Rico, Guam
EU <=> EU (Open Skies)
France <=> French Overseas Departments (Reunion etc.)
USSR => Bases outside Russia remain open after the Iron Curtain falls, so if you are HQ'd in Moscow and open a base in Kiev in say 1985 you can keep it after 1990, but not open there anymore if you close it.
That should be all significant examples.