What is multicultural nations?

A "multicultural nation" is an oxymoron. A nation is a people of common origin, ethnicity and/or culture. A nation is, by definition and in the modern context of the Word multicultural (meaning multi-ethnic), monocultural. A state may be made up of distinct cultural groups and comprise many nations or people from many nations - but that is a state and not a nation. The confusion arises from the conjoining of "nation" and "state" with the rise of the "nation states" in Europe in the 19th century when new states - particularly Germany and Italy - were formed from fractured groups of states and kingdoms where the inhabitants had common ethnicity, language and closely tied cultures.

For example, Australia is a multicultural federation of six states (and two territories) but the term "Australian nation" can only correctly refer to the Aborigines who have inhabited the country of Australia for over 30,000 years - and not to the ethnically European, Asian and others who only have a history up to 235 years in that location.