Abstract: This paper attempts a comparison across time and space, focusing on the transborder homeland nationalisms of Weimar Germany and post-Soviet Russia. Both involve claims to monitor the condition, support the welfare, and protect the rights and interests of external ethnonational kin - persons who are seen as belonging to the state in some way despite being residents and citizens of other states. There are superficially striking parallels between the target populations as well - the ethnic Germans stranded in an array of nationalizing successor states after the First World War, and the ethnic Russians (and other Russian-speakers) similarly stranded after the disintegration of the Soviet Union. Yet while noting these and other parallels, the paper focuses on key differences between the two cases, and between their broader interwar and contemporary contexts.;