The gap in many states between de jure sovereignty and de facto sovereignty is the key obstacle to ensuring global security and prosperity. This paper seeks to define a quantitative index for sovereignty and propose a reorientation of international strategy to overcoming this “sovereignty gap”. It proposes a broad approach that can be tailored to implementation in specific contexts. This approach includes delineating the core functions of the state and its capacity to perform those functions, aggregating these indicators to create a sovereignty index, identifying strategies to build state capacity and proposing a reorientation of the activities of a wide range of international actors.