Contemplating an Uneven Landscape: The Authority of International Law

The concept of the authority of international law defies the common jurisprudential assumptions about the nature of authority. International law’s authority is not typically personified in formal institutions and officials, and it features few formal hierarchies. Thus, unlike that of domestic legal systems, the authority of international law is largely unmediated. Its authority relates primarily to the capacity of its norms to pre-empt the practical reasons of states and other subjects, by making it normatively inappropriate or unacceptable to rely on, and invoke, certain reasons to justify their actions. The unmediated form of the authority of international law is visible even in those contexts where formal institutions such as international courts operate. The factual authority of international courts is highly volatile because their judgments do not always succeed in pre-empting practical reasons. Customary international law is the paradigmatic case of the unmediated authority of norms which represent a balance in practical reasoning. The existence and content of customary rules are determined by the function they perform in shaping the practical deliberations through pre-empting reasons. The interpretation of customary international law is the process of the reconstruction of its pre-emptive function. This function is especially visible in the context of values and principles which international law embodies, such as solidarity. The authority of international law entails that such values are replaced by pre-emptive norms. The unmediated authority of international law entails that the ideal of the international rule of law combines the formal and substantive virtues of the international legal order.