Let’s say I become a citizen of a country that doesn’t allow dual citizenship. During naturalization, new country B tells me I have to renounce citizenship from old country A.
Does that have any effects back in country A? How would country A know? Would country A even care if they found out?
Sovereign citizens, the kind that call themselves American State Nationals, do this by getting a special fake passport from this website that mostly sells moonshine supplies but sells fake passports on the side.
This doesn’t answer your question but I think it’s really interesting so just as an aside.