You said that according to Lawson and Sloane, Resolution 567 referred to "“self-determination” as a minority in a nation-state".  The link I provided to the resolution shows that it says no such thing and Lawson and Sloane do not make that claim.  Perhaps you were confusing the resolution with something else.  And I did not say "a territory cannot exist" in a nation-state or a federal republic.  Clearly it can as an "incorporated territory."  Both Canada and Australia have incorporated territories for example.  (Although they are not technically "republics".)  Obviously if a country has territories, it will exercise some degree of jurisdiction over them and may allow them some degree of self-government, but that does not incorporate them.