After decades of relative silence, the study of frontiers and boundaries is resuming a prominent place in political geography. The impetus for the revival of limology (border studies) comes from the global context of a post-Cold War order, which has led to challenges to existing political arrangements, and from the identity turn in human geography and related disciplines. The study of frontiers and borders needs to be integrated into the main theories of the discipline. World-system theory, long criticized for its lack of a territorial footing, offers an opportunity for extension of its three geographic scales (world-economy, nation-state and locality) to incorporate two newly-emerging spatial dimensions at the macro-regional (bloc) and sub-national levels. Global and geopolitical trends, as well as shifting identities at national and sub-national scales, are reviewed and their effects on the changing scales of territoriality are reviewed. A geographic model illustrating the shifting and overlapping nature of borders is developed based on the contemporary developments in Eastern Europe. The case of contemporary Ukraine, as an example of state-and nation-building, shows these geopolitical changes as complex and dynamic.