People can exert self-determination over where they live without necessarily expelling or displacing anyone else. That's all I mean. People can coexist together in an area and mutually control that area. A main issue in the world today is imperialism by western powers. Israel is a major culprit of this. Self-determination in this sense often means the ability for a people to control their own political, economic, social, etc formation without the external threat of imperialism. Vietnam wanted to be rid of French influence, various socialist movements of Latin America wanted to be rid of the CIA, and Palestine today wishes to be rid of the US and Zionist interference.