Strangely, there appears to be next to nothing in the mainstream political philosophy literature (though maybe I’m missing something), that drives home the arbitrary distribution of citizenship. It’s funny, because citizenship, unlike wealth, can be created out of thin air, and is distributed according to a few largely arbitrary principles.
Further, in starkly physical terms, it's not as though citizenship is some positive entity that we're simply omitting to provide. A non-citizen is not lacking in any intrinsic capacity. What citizenship provides is permission -- it simply serves to remove the obstructions we would otherwise place in their way. In other words, social resources are liberties, and arguably should be considered the natural 'default' or baseline position. Citizenship isn't something we grant; it's something we cease to deny.
So: is the current global allocation of social resources just? Or should, for example, functioning societies deny citizenship to fewer people?
[Cross-posted to the International Network for Ethical Issues in Resource Allocation blog.]
P.S. Note that money, likewise, is arguably more a social than material resource, in the above sense.