The idea of a Jewish invasion in Romania appeared during the debates on the first constitution (1866) and was revitalized after 1918, as the recently occupied territory of Bessarabia hosted many Jewish groups fleeing revolutionary Russia, the civil war, and pogroms. In this context, the immigrants were depicted by nationalist propaganda as invaders wishing to exploit Romania’s wealth and hospitality, and this image was combined with the myth of Judeo-Bolshevism. Thanks to the archival sources of the High Commission for Refugees and of relief organizations such as the Joint Distribution Committee, this paper aims to present in detail the controversial encounter between national security policies and humanitarian concerns for the fate of the refugees. At the same time, it will discuss how the refugee question influenced the Romanian political context, fostering sentiments of antisemitism and xenophobic anxiety. As will be argued, the idea of an invasion was very influential before and after World War I, and conditioned not only the definition of the policies regarding citizenship and minorities, but also the whole political discourse and the shaping of Romanian identity. At the same time, the emergence of refugees and the juxtaposition of humanitarian versus national security was not a purely Romanian affair, and in many aspects anticipated the topics of today’s debates.