Cosmopolitanism and its theory of universal justice are motivated by three distinct principles:

1. A commitment to the moral belief that our obligations to distant others are of no lesser priority than those to our compatriots.
2. A belief that global problems require global political strategies.
3. An understanding that the boundaries of the modern nation-state are arbitrary, and therefore should not be used to excuse or explain inequalities between people.

On the other side of the debate, the anti-cosmopolitan position is bolstered by two sets of concerns:

1. Criticisms regarding the desirability and feasibility of a global state.
2. Concerns regarding the moral universalism that subtends the cosmopolitan position*.

*In particular criticism has been levelled at moral universalism, fearing that it devolves into imperialism, with particular moral values imposed as universal truths. 

However, taken too far, anti-cosmopolitan worries over ethnocentrism and imperialism may cripple efforts to help distant or different others.

In a very abstract sense, all morality must be cosmopolitan; it must include the possibility of bridging the distance between the self and the other, whether that distance be geographic or ontological  (based on the idea that in some fundamental sense we are all different beings).

In this light, any radical cultural relativism, insisting on epistemological limitations that make it impossible for one group to understand and judge another, threatens to cut short the very impulse to help others in need.

Whether you follow cosmopolitanism or not, it is important to avoid immediate dismissal of its theories, to prevent limiting your individual ability to promote global justice.

K. Walker “Is Rooted Cosmopolitanism Bad for Women?”, Journal of Global Ethics 8 (1) 2012: 77-90.