The Black Sea region has emerged as a critical geopolitical focal point amid the contestation of the liberal international order, particularly highlighted by the ongoing conflict between Russia and Ukraine. This chapter examines the Black Sea as a strategic nexus, vital for energy and food flow among riparian states, while emphasizing its role as a regional security complex. The analysis underscores the implications of Russia’s military actions, which threaten freedom of navigation and challenge Western interests. Increased Russian assertiveness in the region, mirroring that of China in the South China Sea, turns the Black Sea into an increasingly perilous theater, necessitating a recalibration of NATO’s strategy in the region. The chapter argues for enhanced cooperation among regional states and a strengthened NATO presence to safeguard critical infrastructure and uphold the rules-based international order.