National citizenship is challenged by two contrasting claims: a state's exclusivity in determining the conditions for inclusion of its own citizens, and the universal inclusiveness of everyone within and beyond national boundaries. Globalisation has increased the demand for human rights, the recognition of identity and culture, and social justice. Today, however, many persons cannot meet the conditions prescribed by national citizenship. This article considers an alternative model: cosmopolitical citizenship, which is based on Kant's jus cosmopoliticum. This third level of law allows all world citizens to exercise their rights and duties in multiple sites of political and legal responsibility. The article has five sections. First, Kant's cosmopolitical conception is defined. Relevant interpretations by Derrida, Bobbio and Beck expand on this definition. The subsequent analysis engages with recent writings by Benhabib, Balibar and Isin, and within that theoretical context considers the European Union's dual citizenship, regarded as a precursor of the cosmopolitical, but contested by Bigo. Notwithstanding, these authors are experimenting with cosmopolitical citizenship. Fourth, influences of Web 2.0 technologies on citizenship are discussed. Fifth, a synthesis of the conceptual and substantive developments in the citizenship debate reveals an increasing acceptance of the cosmopolitical principle, and its capacity to render citizenship more fluid and responsive as seen through the eyes of others.