In Liechtenstein, giving up your old citizenship is a prerequisite for naturalisation. Nevertheless, the 2015 census shows that almost a quarter of all Liechtenstein citizens resident in the country are dual or multiple citizens. Liechtenstein has a so-called asymmetrical system as regards dual citizenship. While the retention of the old citizenship is not allowed in the case of naturalisation, Liechtenstein citizens who become naturalised in another country can retain their Liechtenstein citizenship and thus become dual citizens, if the other country allows this. What is Liechtenstein's position with regard to dual citizenship in Europe? How has Liechtenstein argued for or against dual citizenship?