Modern international law tends to grant a right to “remedial self-determination” only in extreme cases. Unfortunately, this position accepts that states ought to be free to violate human rights so long as the abuses fall short of war crimes and genocide.
I'm definitely in favor of a radical expansion of self-determination. It seems clear to me that the burden of proof belongs on whoever is claiming the right to rule over others, rather than on those who do not want to be ruled over.