This thesis examines the geopolitics of sustainable transport, focusing on the ways in which geopolitical disruptions interact with efforts to decarbonize global mobility systems. Transport is both a critical enabler of globalization and a major contributor to climate change, responsible for nearly one quarter of global energy-related emissions. At the same time, it is deeply embedded in international politics, where chokepoints, strategic corridors, and resource dependencies shape the flows of goods and energy. The study argues that sustainable transport cannot be understood in isolation from geopolitics, since the transition to low-carbon systems generates new vulnerabilities and dependencies while geopolitical events directly influence environmental performance and long term transitions. The research combines a literature review with qualitative case study analysis to address three guiding questions: how geopolitical events disrupt transport flows and infrastructures, what the short- and long-term sustainability impacts of such disruptions are, and how states and systems adapt in response. Three cases were selected for their global significance and diverse mechanisms of disruption: the 2021 Suez Canal blockage and the Russia–Ukraine war. These cases reveal that disruptions not only cause immediate logistical and environmental costs, but also catalyse systemic adaptations, including diversification of routes, investment in renewable infrastructure, and strategic reshaping of global supply chains. The findings demonstrate that the geopolitics of sustainable transport involves both risks and opportunities. Disruptions expose fragilities and increase emissions in the short term, but they also accelerate long-term transitions toward resilience and decarbonization. The study concludes that effective governance of transport requires an integrated approach that recognizes its dual role as both a technical infrastructure and a strategic geopolitical instrument.