Whelan noted that the concept of democracy "always makes reference to a determinate community of persons (...) who are collectively self-governing", yet the drawing of the boundaries of such communities "is a significant problem for democratic theory and practice" and "democratic theory itself offers no clear guidance on the matter.
Immanuel Kant in his work Perpetual Peace argued that sovereign states owe certain rights of "world citizenship" ("Weltbürgerrecht") to aliens within their jurisdiction.
Their boundaries may have been established by historical accident, by acts of autocracy, or war, or imperial bureaucracy; what, then, makes them legitimate instead of some other possible constellation of democratic communities comprising the same individuals?
Frequently, a referendum is proposed as a peaceful and democratic way of resolving a sovereignty dispute, but the question then becomes one of deciding who is eligible to vote and who is not, that is, where the boundaries of the proposed community are to be drawn for the purpose of democratic self-determination, a question complicated by the fact that in most geographical territories, ethnic, religious, and other groups co-exist and overlap in varying proportions.
Another case of the boundary problem is a conflict between the claim of an ethnic group, such as an indigenous people, to limit participation to those with a shared ethnic heritage and to exclude colonialist settlers or historical occupiers or their heirs, and the claims of individuals of the latter groups to be included in the democratic process in what is de facto their homeland.