Ethnic discrimination, legal or unofficial, against culturally distinguishable groups, on the grounds of race, religion, language or nationality, may be subtle or overt. It may be for economic exploitation and gain, or for social status or ego.
The term "race" has in most cases been used by the dominant group (usually white) implying a superiority/inferiority relationship. "Ethnicity" does not necessarily entail any such ranking, but there may be conflicts between ethnic groups for numerous reasons: control over land, political influence, predominance of culture, religious struggle, affiliations to people in other countries, and the like. This is further aggravated by transmigrations of groups of people. There is a delicate balance between prevention of discrimination and protection of minorities to safeguard the maintenance of a separate identity for each minority as a group.
Of the 132 major states with more than one million inhabitants, only 12 can be described as ethnically homogeneous. Of the remainder, a single ethnic group constituting 90% of the population occurs in 25 states, between 75 and 89% of the population in another 25 states, and between 50 and 74% of the population in a further 31 states. There are 39 major states where no single ethnic group accounts for half of the population. In other words, the homogenous nation-state is an exception. If each ethnic group were given a nation-state of its own, there would be several thousand states.
In Belgium, the Vlaams Blok political party centred in Antwerp aspires for an ethnically pure Flanders (which would include Brussels, even though less than 15 percent of the capital's current population in Flemish). It's published three-phase plan particularly focuses on non-Europeans: immediate expulsion of all illegal immigrants, those unemployed for five months or more and those with criminal convictions in phase one; deportation of first generation foreigners in phase two and of the second and third generations in phase three.