No sovereignty is "incontestable."

The contest is only just beginning. The relative power between sovereigns is shifting, and those who perceive their sovereignty to be illegitimate (imposed upon them by others), outgrown (relative power shifts make them reasonably perceive they deserve a larger slice of the pie), or simply see opportunities to expand in some way, are already working to do so.

This is how it has always been, and how it will always be. We have a false sense of what "right" looks like due to the artificialities of the post-WWII stand off between East and West. The reality is that what "right" looks like is an ever-changing thing and that nothing in nature is more unnatural than stasis.