An important but hardly-known international agreement signed by 29 European countries has established common principles for citizenship rules, rights and duties associated to multiple citizenship, explains Claudia Delpero. It's called the European Convention on Nationality. The agreement also clarifies the military obligations for people with multiple nationality, a topic becoming increasingly relevant as countries like Germany and France are discussing the reintroduction of military conscription. Last Friday, the German parliament approved a landmark law that brings back the military service on a voluntary basis, with the possibility to extend it to needs-based recruitment.