Article1, part 2 (UN Charter) states that purpose of the UN Charter is: “To develop friendly relations among nations based on respect for the principle of equal rights and self-determination of peoples, and to take other appropriate measures to strengthen universal peace”
The Universal Declaration of Human rights, “the will of the people shall be the basis of the authority of the government”
ICCPR, ICESCR, “All peoples have the right of self-determination. By virtue of that right they freely determine their political status and freely pursue their economic, social and cultural development.”
Doctrine of uti possidetis juris , meaning that old administrative boundaries would become international boundaries upon independence, even if they had little relevance to linguistic, ethnic, and cultural boundaries was generally accepted to avoid unending claims cutting across international boundaries.
After 1990s there has been a fresh challenge to the concept of territoriality.
No discussion on self determination can be complete without mentioning the Kashmir issue. For a long period it was looked upon by the Western powers as a disputed area. However of late, positions have undergone a change. Though Pakistan continues to raise the issue there is a near consensus that the issue will have to be resolved with mutual consent.