This thesis aims to analyse the normative rationales behind non-citizens' legal standing in two liberal nation-states. The thesis takes the cosmopolitan and communitarian rationales as its theoretical starting point. Specific attention is given to the possibility of coherently combining the cosmopolitan and the communitarian rationales. The thesis analyses the actual legal standing of non-citizens in the U.S. and Germany and so links the political theoretical discourse to alienage jurisprudence. The conclusions drawn are that both the cosmopolitan and the communitarian rationales underlie non-citizens' legal standing. The treatment of noncitizens is fairly normatively coherent and in line with a weak cosmopolitan perspective. The thesis, however, identifies limited but important normative contradictions in the treatment of non-citizens and outlines, on a practical level, what is required to remedy this situation.