In the nineteenth century, states learned to rule through records: censuses, passports, registries, and archives that made populations legible to law and taxation. In the twenty-first century, the record has become continuous. Sensors, platforms, and clouds turn everyday life into durable traces, and storage is cheap enough that "temporary" collection often becomes permanent by default. The strategic question is no longer whether states will seek informational advantage, but how that pursuit reshapes national power when memory is effectively infinite. State of Data argues that data power is not a contest of who collects the most. It is a contest over control: over infrastructure, over rules, and over the institutional capacity to use information without losing the consent that makes governance possible. Kiran Solvay examines platform dependence and cloud governance, the hard choices behind data localisation, and the ways privacy regulation functions as both a constraint and a tool of statecraft. Across security, markets, and public administration, the book shows how standards, procurement, and oversight quietly determine whether data systems produce resilience or fragility. Written for students, policy audiences, and general readers of geopolitics, the book provides a structured lens for assessing national capability beyond headlines about innovation or surveillance. Readers will come away able to map the real control points in data systems, to distinguish technical possibility from lawful authority, and to see why legitimacy and trust are not soft values but strategic resources. The result is a clearer understanding of what sovereignty can mean in an interconnected world, and what resilient governance demands when forgetting is no longer guaranteed.