Many countries allow dual citizenship, so I'm not sure just getting citizenship somewhere else is enough in every case. I'm not sure the specifics of when they

Many countries allow dual citizenship, so I'm not sure just getting citizenship somewhere else is enough in every case. I'm not sure the specifics of when they deny renouncing citizenship, but if you don't have citizenship somewhere else or your visa to that country is as a U.S. citizen, I could see those as being valid cases for rejection until those are resolved (also if you have outstanding warrants or are under investigation for something).