The book provides a comprehensive understanding of the unfolding geopolitical changes in the South Caucasus in the age of increased great power competition across Eurasia. Recent research on the geopolitics of the South Caucasus focuses either on interstate relations among Armenia, Azerbaijan and Georgia or on each of regional actor's (Russia, Turkey and Iran) ties with the region's one or all three states. Little attempt has been made to see the region's shifting geopolitical importance from a global perspective: growing US-China rivalry and shifting balance of power in Eurasia; recalibration of the US' military and diplomatic vision in western Eurasia to adjust to the Chinese challenge. The book argues, from a theoretical point of view, that the increased competition in the region fits into the global pattern of unfolding great power competition, when military and economic calculations drive regional powers to increase their influence on immediate neighborhoods sidelining the collective West from the negotiating table and the emerging new security architecture.