How did nationalism impact ethnic and cultural identity on a global scale? Please Help asap

Nationalism is a worldview that takes its starting point in the community within the borders of nations. Nationalism pays homage to the nation, culture, history and safeguards the nation state and its interests. Anyone who professes nationalism is called a nationalist.

Thus, the conception of nation also implies for nationalists the existence of a people, that is, a society with common cultural and ethnic characteristics that differentiate it from other nations, and give individuals a sense of belonging to that nation. In this way, nationalism can promote in certain cases clashes between that ethnic and cultural identity and the cultural expressions or minority ethnic identities found in a given society or nation.