How did nationalism threaten the existing political order of the nineteenth century?

Nationalism created the feeling of superiority towards other country.

This influence many countries to raise their arms and make various invasions towards other countries to spread the power of their country

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Americans often speak of their country as one of several large regions.  these regions are cultural units rather than governmental units --  formed by history and geography and shaped by the economics, literature and folkways that all the parts of a region share. what makes one region different from another? a region's multicultural heritage as well as distinct demographic characteristics like age and occupation make regions different and special. within several regions, language is used differently and there are strong dialects. there are also differences in outlook and attitude based on geography.