Cosmopolitan approaches to International Relations have generally fail
ed to address the practical implications of their postulates. This pap
er examines how one international social movement-international social
ism-attempted to put the theoretical tenets of cosmopolitanism into po
litical practice. The author explores the various obstacles encountere
d by the movement and, based on this analysis, it is argued that two h
istorical forces-class and the state-should lie at the centre of any r
eformulation of cosmopolitan politics.