This paper focuses on the analysis of convergence and divergence as modern social and economic processes on the territory of the Russian-Ukrainian borderline. The authors on both sides of the border draw special attention to the evolution of integration and disintegration processes in the border regions, both in the pre-crisis and post-crisis periods of relations between two countries. The 2004–2018 period has been chosen for the current research as it includes dramatic processes of convergence and divergence in the Russian-Ukrainian border area. Particular attention is given to the analysis of a set of relevant factors affecting the dynamics and transformation of the social and economic landscape of the border regions of the Russian Federation and the Ukraine; the main trends of geopolitical contradictions are highlighted as well, the vulnerable links of the territorial socioeconomic systems of border areas, both in a resettlement and in the economic sense, are identified. Socioeconomic factors of convergence and divergence are estimated and evaluated in order to develop the idea of interconnection and interaction of the borderline territories. The authors point at the asymmetry in demographic, migration and economic correlations which are reflected in the transformations and deformations of border regions after the year 2014. The processes of convergence and divergence of demographic and economic indicators of the border administrative divisions of the Russian Federation and the Ukraine are analyzed based on the current statistical materials and calculated integral indicators (coefficient of variation and Theil index) using a comparative approach. The processes of divergence both in the economic and social spheres at equal pace prevailed during the above-mentioned period of time. In conclusion, the authors infer that disintegration processes contribute to the increase of the divergence of the Russian-Ukrainian border area and disrupt the common market for goods, capital, services, and labor that has developed over a long period of time.