Preferences and Compliance with International Law

International law lacks many of the standard features of domestic law. There are few legislative or judicial bodies with exclusive authority over particular jurisdictions or subject matters, the subjects regulated by international law typically must affirmatively consent to be bound by it, and supranational authorities with the power to coerce states to comply with international obligations are rare. How can a legal system with these features generate changes in state behavior? For many theories, the ability of international law to inform and change individual preferences provides the answer. When voters care that treaty commitments be kept, or that international norms be honored, the theory goes, leaders are more likely to be able to make choices consistent with international obligations. Over the last decade, a literature has emerged testing these theories using surveys and experiments embedded in surveys. Multiple U.S. studies find that international law and international norm arguments shift public opinion in the direction of greater compliance by 4 to 20 percentage points. However, studies in foreign contexts are more mixed, with some backlash reported in countries in which international law is highly politicized. This Article describes the state of current knowledge about whether international law actually does change preferences, explains the limitations with existing research, and proposes avenues for future study.