The shock of the First World War resulted in a range of initiatives that, on the artistic level, radically called into question a number of fundamental concepts. While the function of new art was a topic that was discussed in different European countries, the international orientation of each national art differed from country to country. In Belgium, this was a complex issue. Notions such as ‘literature’ and especially ‘internationalism’ became the subject of a harsh battle for definition that was carried out in several literary and artistic magazines. In this article, I look at how these terms were defined within the artistic group surrounding the Brussels magazine L’Art libre (1919–22). I will give a general definition of internationalism in order to then elaborate the extent to which it may come into conflict with a focus on local, Flemish reality. As a social entity, Flanders did indeed fit into the internationalist program to recognize suppressed nations. Yet as an artistic entity, its existence was more problematically situated within a tendency for ever-increasing artistic internationalization. My analysis will show a number of discursive and argumentative strategies used by writers and critics in order to legitimate the idea of ‘Flanders’, both as a literary and as a social entity.