Pacta Sunt Servanda and Empire: A Critical Examination of the Evolution, Invocation, and Application of an International Law Axiom

In public international law, pacta sunt servanda is the foundational principle that international agreements are binding on treaty parties and must be kept. Insufficient attention, however, has been given to the role played by this international law axiom in organizing and shaping the international legal order. Accordingly, this note undertakes a critical historical analysis of how pacta sunt servanda was, and continues to be, applied as a legal basis and used as an argumentative method for the formation and maintenance of empire despite its conceptual evolution across time. Importantly, it does not argue that pacta sunt servanda should be abandoned as an international law rule or that pacta sunt servanda is not essential to the functioning of the international legal order. This note instead examines the conceptual evolution, invocation and application of pacta sunt servanda, and its relation to informal empire, across time.