Rules, Defeasibility, and the Psychology of Exceptions

Abstract

An important aspect of international law is that it typically lacks the formal, structured, and institutional enforcement and sanctioning mechanisms of domestic law. As a result, decision-makers constrained by international law are often faced with applying the rules of international law to their own action. We know from H.L.A. Hart and others that such internalization is possible, but we know from a great deal of experimental research in cognitive and social psychology that imposing second-order constraints on one’s first-order preferences is difficult and rare without a sanctioning mechanism. As a result, there exists a serious risk that treating the rules of international law as defeasible and subject to exceptions will render the constraints of international law ineffectual when actors are making the decisions about whether and when the exceptions to constraining rules apply to their own actions.