Diversity in national level along ethnic, racial, religious and linguistic lines is a reality in most countries of the world. The author in this article, accounts the rise of ethno - nationalism as outcome of politicized ethnic groups in modernization process and differentiats the ways dealing with ethnic minority diversity in western countries with developong countries.
Studying interdisciplinarily, the author, accounts the marxist, liberal, premordial and constructivist theories to ethnicity and examines possible vulnerabilities of solidarity and national integration of developing countries differentiating "Integration" from "Assimilation" in "Nation – Building process", the author makes relationships between the achievement of integration goal and the rise of civil society and sufficient distribution of social, economic and political resources.