In a sovereign republic sovereignty resides in the people. Hence there should be no discrimination on the basis of language grouping or ethnicity or religion, colour, political affiliation, gender or any other demographic characteristic.
However if the citizens of a sovereign republic are gripped by xenophobia and display hatred against other groups on the basis of ethnicity, gender, religion or other reasons, national unity, cohesion and peace would be the casualty. No nation could be at peace with itself if its people are divided into sectarian groups. Hatred could only breed more hatred until a country is consumed by civil war.
This is why a country as rich as Democratic Republic of Congo is still wallowing in poverty despite all its mineral resources. The same goes for South Sudan. Mineral resources or oil would not benefit a people at war. Peace is a greater source of prosperity than mineral and oil resources.