What can justify a global basic structure? I argue that states are involved in global collective action which imposes certain duties on them. The effects of this collective action are felt at state level: some states bear its costs, while others enjoy its benefits. Yet all have a duty to develop a global distributive system as to fairly share these costs and benefits associated with global collective action. One example of global collective action is global warming. I point out that states should share the costs (relief from natural disasters) and the benefits (natural resources that can be exploited as a result of global warming) insofar as they are a consequence of collective action involving all states. If so, then states should also support the development of global institutions and international law that can provide the framework for a fair distribution of the costs and benefits associated with global warming.
