And it can cause headaches with people being stateless because neither the country of their parents nor the country of their birth recognizes them. And that's something that's normally prohibited by treaty: you can't take an action that will render someone stateless.
Is that really so? It seems odd because not every country has soil-based birthright citizenship. So, there must be some combinations that will result in a stateless person (although I would expect that this is an exceptional case that is just handled as an exception).
Where? I haven't really heard of many cases like this. Usually the most abuse that happens is someone "forgetting" their citizenship and trying to gain asylum, because they know they can't get citizenship otherwise, anyway.
