Ludwig Biller (Director Public Sector and Defence, Strategy&) outlines on the blue sofa at the Berlin Security Conference 2025 how European sovereignty depends on tightly interconnected enabling factors. He highlights supply chain resilience, sustainable defence financing and control over the defence technology stack as mutually dependent pillars that require second-order thinking beyond troop numbers or procurement budgets. Biller assesses Europe as increasingly exposed to geopolitical risks from great-power competition and the return of tariffs, arguing that sovereignty must be built through resilience, alliances and strategic interdependence rather than autarky. He stresses the importance of owning critical technologies and intellectual property, closing financing gaps for defence innovators through institutional capital and hybrid public-private models, and translating strategy into capability via strong ecosystems, rapid prototyping and decentralized mission command.