The first section of this paper delineates a framework which proposes a set of core functions that a sovereign state must perform in the modern world. This functional delineation provides a framework for the calculation of a sovereignty index, through which the sovereignty gap can be measured in a tractable fashion. Once this more quantitative framework is in place, the progress of or decline in state capabilities to perform each function severally and collectively can be assessed. Moreover, the index would also allow an overall assessment to be made of whether the multiplicity of interventions by the multiplicity of international actors is closing or opening the sovereignty gap. The second section of the paper outlines some of the constraints that exist in the current international system. Mindful of these constraints, the paper then proposes a reorientation of the international community's approaches to fragile states through the introduction of state-building or sovereignty strategies. These would be long-term compacts - entered into by a country's leadership with the international community on the one side and with its citizens on the other - that integrate the current raft of interventions in the economic, political, security, judicial, administrative and social domains into a single strategy designed to close the sovereignty gap within each of the core state functions and in the state as a whole. The functional delineation proposed would allow strategies to be designed that are both universal, acknowledging that all states must perform a number of services for their population to meet their needs, and also tailored to context, in that the route taken to develop institutional capability will vary from country to country.