False dichotomy. Nationalism and Imperialism are not mutually exclusive categories. See the First Empire of France and rise of Napoleon Bonaparte which was both nationalistic and imperialistic to the nth degree, or the Turkish control of the Ottoman Empire. Also there was Italy under Mussolini which acquired colonies in North and East Africa whilst being nationalistic, or even modern day Russia being a nationalist ethnostate with numerous devolved non-Russian nations under it's Federation (which mind you is still waging wars of conquest in Eastern Europe).
The nationalistic impulses will be mainly felt and propagated by the dominant ethnic group in any 'empire' or imperialist nation, while the minorities are generally expected to assimilate to that dominant ethnoculture if they want to have hope of advancing in their station.
(post is archived)