By definition, a government in exile is spoken of in terms of its native country, hence it must return to its native country and regain power there in order to obtain legitimacy as the legal government of that geographic area.
A government in exile is spoken of in terms of its native country. This was by definition. It must return to its native country. This is by definition. It must regain power there. This is by definition. This is to obtain legitimacy as the legal government of that geographic area.