>3. national referendum
A fair vote by the people in these areas assures the world that these territories are not controlled by an unwanted force and is mandatory to find out what the will of the people is, because only then will their never be a dispute about it. An as part of this referendum, it should never be a one time thing, but should be renewed every 20 years and kept transparent until there is at least a consistent vote 5 times over a century. This will make no bones about the matter.