I guess that My point of View would be that criteria which were established by the Declaration of Independence in 1776.

First the people announced their separation from the former country. And then legally established by elections a new Government by which they chose to be Governed by.

By announcing their separation from their former associations, they were no longer bound by the laws of that Country therefore when they chose their New government and became bound by it laws they were an Independent nation as the 13 Colonies were.