He has advocated the rights of many minorities and indigenous peoples to autonomy and self-determination in United Nations fora and before parliamentarians in the European Parliament, including the Armenians of Nagorno Karabagh, the Saharaoui population of Western Sahara, the Tamils of Sri Lanka, the Bubis of the Island of Bioko/Equatorian Guinea, the Catalans of Spain, and the Igbos and Ogonis of Nigeria. de Zayas is an advocate of reviewing certain decolonization issues in the light of the UN Charter and General Assembly resolutions. In particular, he has criticized the Spanish amalgamation of the distinct Bubi people of Bioko Island with the people of another Spanish colony, Equatorial Guinea. Spain amalgamated the two just before "decolonization". The result was that the Bubis were denied self-determination and instead of having Spain as the "master", now they have Equatorial Guinea.