This collective monograph offers a comparative analysis of the political systems of the regional countries using the methodology of the Stability Index of Political System. Specifically, it examines the trends and transformations in the political stability of Armenia, Georgia, Azerbaijan, Turkey, Iran, Russia, and Ukraine. The selection of countries is driven by the complex geopolitical developments in the region, new initiatives by key players, and shifts in power dynamics. The work includes both in-country and cross-country analyses. The in-country analysis covers a comprehensive study of the political, economic, and social factors influencing stability in the regional countries during 2000-2021/2022. The cross-country analysis examines the comparative indicators of political stability for the mentioned countries in 2022. This book is intended for scholars, experts, and students at universities and research centers.