The second episode of the Cities and Geopolitics series turns to the material architectures through which geopolitical power is organised and exercised. From energy grids and digital networks to ports, logistics hubs, and semiconductor infrastructures, contemporary geopolitical rivalries are increasingly mediated through complex, often invisible, urban systems. This episode explores how infrastructures are not merely technical backdrops to global politics, but strategic assets and active instruments of power. Our guests examine how infrastructures are designed, financed, and governed in ways that embed geopolitical priorities, whether through the securitisation of supply chains, the territorialisation of digital systems, or the reconfiguration of energy networks in the context of climate transitions and resource competition. At the same time, the conversation highlights how these large-scale infrastructural transformations are grounded in specific urban contexts. It considers how cities become key sites where global ambitions materialise in concrete forms, such as data centres, ports, corridors, and grids, and how these infrastructures reshape urban space, governance, and everyday life. In doing so, the episode foregrounds the uneven geographies of infrastructural development, asking who benefits, who is marginalised, and how these systems are contested on the ground. Moving between planetary strategies and situated urban experiences, our guests invite listeners to rethink infrastructure not as neutral or purely functional, but as deeply political, contested, and central to the making of contemporary geopolitics.