This chapter analyzes the use of public morality as a defense to international obligations. It considers whether and under what circumstances a nation is required to adhere to international agreements when those agreements involve morally questionable practices against animals. A case study of the current World Trade Organization (WTO) complaint by Canada and certain Scandinavian countries against the European Union’s (EU’s) import ban of certain seal products is examined to illustrate this inquiry. Part I provides an overview of the EU seal product ban. Part II addresses Article XX of the General Agreement on Tariffs and Trade (GATT) and its chapeau as the framework for a public morality defense. Part III considers this defense in the environmental protection and animal welfare contexts to underscore how the evolution of environmental protections provides a plausible roadmap for the continued development of animal welfare protections. Part IV offers some recommendations on animal welfare development based on the historical and current developments in public morality in the context of international trade.