Flemish is a language that is related to Dutch dialect and is spoken in the northern part of Belgium. Yes, it is used as a separate language to reduce the conflict between the French and Dutch-speaking community.
Belgium has complex ethnicity because two communities, German and Dutch-speaking respectively form the majority of the population.
According to its Constitution, the Dutch and the French-speaking minister should be an equal number in the central government. Hence no single community can make the decision unilaterally.