Most - if not all - conflicts in international relations have - to an extent - something to do with sovereignty. On the theoretical side, we learn at University that either considered as a strong concept or one that has lost relevance, it is still discussed. On the practical side, the prerogatives a State has over its people and territory appear to be the highest. Within these ideal and real backgrounds, there are various sovereignty disputes around the world that struggle between legal and political limbo, status quo and continuous tension with various negative consequences for all the involved parties (e.g. violation of human rights, war, arms trafficking, only to name a few). It is increasingly clear that the available remedies have been less than successful, and a peaceful and definitive solution is needed. This thesis proposes a fair and just way of dealing with certain sovereignty conflicts. Part One presents the core argument to work out the structure upon which this thesis will be developed. There is a traditional idea that sovereignty must be unshared and unlimited. I argue that in actual fact both in theory and in practice sovereignty is always limited. Thereby, I consider how shared sovereignty is possible—how a State can limit itself and stay sovereign. Chapter One, the Introduction, presents the basic constitutive elements of this thesis. Chapter Two examines if sovereignty can be (in fact, may actually be) limited, and therefore can be shared. To show this I use both criticism of the best known theories of sovereignty and investigation of the historical facts. Part Two explores the minimum elements that must be acknowledged conceptually, legally and realistically in order to give flesh to shared sovereignty and the way it needs to work if we want a peaceful understanding amongst the parties concerned. Chapter Three appraises ‘shared sovereignty’ and similar expressions used in political and legal literature. In order to do that, I show which notions of shared sovereignty are not relevant. Chapter Four examines how a relevant notion can be developed, using the analogy of self-ownership. Chapter Five discusses the main remedies applied at international level in sovereignty issues and why proposed alternatives to shared sovereignty will not solve the problem. Part Three considers how distributive justice theories can be in tune with the concept of sovereignty and explores the possibility of a solution for sovereignty conflicts. I argue that shared sovereignty can be that solution based on Rawlsian principles. Chapter Six introduces and explores a new conception of shared sovereignty. Chapter Seven evaluates what sorts of institutions and arrangements could, and would best, realise shared sovereignty so defined by showing in outline how it might be applied to territory, population, government and law. Chapter Eight brings together the main points of this thesis, and shows possible further implications.

Aujourd’hui encore, notre vie politique est organisée autour de la relation de commandement à obéissance à laquelle nous oblige la souveraineté politique. Mais ce rapport d’obligation est une forme particulière du pouvoir politique, qui émerge au XVIe siècle à travers la pensée de Bodin, dans une conjoncture historique précise. Comment ce concept, renvoyant à l’obéissance absolue et inconditionnée des « francs sujets » à leur Souverain, a-t-il pu être conservé par les sociétés démocratiques modernes? L’indivisibilité et la transcendance de ce pouvoir peuvent-elles exprimer la souveraineté du peuple? C’est une première métamorphose de ce concept qui est requise pour traduire la forme républicaine instituée suite aux deux révolutions américaine et française du XVIIIe siècle. Se pose alors la question de savoir comment conjuguer la nécessaire obéissance aux pouvoirs publics avec la liberté humaine. L’obligation d’obéir à laquelle nous sommes tenus par l’autorité souveraine n’est-elle pas en effet assimilable à une limitation de cette liberté? Et tout pouvoir ne tend-il pas, par nature, à s’hypertrophier? Comment assurer les citoyens de la préservation de leurs droits subjectifs, tout en veillant à leur coexistence en communauté? L’étude la république fédérale américaine permet d’appréhender l’interaction particulière qui existe entre une certaine représentation des fonctions du pouvoir politique, et une dynamique sociale puissante et entreprenante. En divisant la souveraineté, les Américains en contredisent un des traits posés comme essentiels, provoquant ainsi sa deuxième métamorphose. Jusqu’où peut-on alors aller dans la remise en cause des attributs souverains, sans perdre la relation de pouvoir spécifique qu’elle inaugure / Even today, our political life is built on an interaction between command and submission, to which we are bound by political Sovereignty. But it is a particular form of the political power, that raised in the 16th century with Bodin’s intellectual contribution, from a precise historical juncture. How this concept, referring to the absolute and unconditional submission from the « free subjects » to the Sovereign, also pertains to modern democratic societies? Are the indivisibility and transcendence of this power appropriate to express people’s sovereignty too? Identifying a first metamorphosis of this concept is necessary, while assessing its transcription into the republican form of government set up by the two American and French Revolutions in the 18th century. Then it became relevant to question how to combine the necessary obedience to public powers with human liberty. Isn’t the obligation to submit to which we are compelled by a sovereign autority, a limitation of this liberty? Isn’t it in the nature of every power to turn abnormally large and invasive? How to ensure both the preservation of the subjective rights of the citizens and the citizen’s coexistence in a society? The study of the American Federal Republic allows us to describe the particular interaction between a certain representation of the political power’s fonctions, and an efficient enterprising social dynamic. By dividing the sovereignty, the Americans contradict one of its essential presumed features, initiating its second metamorphosis. To what extend, then, can we challenge the attributes of sovereignty, without losing the specific relation of power that its inception inaugurated