Borderlands are by definition realms where certainty wilts and categories fade.
In borderlands there are no right answers. Ambiguity is the norm. The changes have been so frequent and confusing that Eastern Europe remained until not long ago the domain of the super-specialist, a researcher driven often by ethnic allegiance and hence suspect to the guild as a whole. The Eastern Europeanist was bound to be a partisan, it was thought, often of fanatical stripe, and hence deservedly marginalized. Today Eastern Europe is in.