Ethnicity has been not only the source of diversity but also social and political tensions across the globe. The socio-economic and political alienation and sense of deprivation trigger ethnonationalism that manifests itself into different forms and manifestations ranging from armed struggles to political movements. The failure to establish a vibrant and pluralist society with social and economic justice at its heart paves the way for ethnic strife that attracts different responses and reactions from the states faced with the ethnic conflict. Based on the qualitative research methods, this scholarly endeavor seeks to dissect the dynamics and drivers of ethnic-nationalism and how the countries like India, Afghanistan, Ethiopia, Switzerland, the Philippines and South Africa have tried to address the problem. Further, it analyses the different theoretical approaches, notably primordialism, constructivism, instrumentalist, language and power, religion, race and culture have been employed by the countries to tackle the non-traditional threat posed by ethnonationalism.