By Gregory C. Shaffer & Mark A. Pollack. Full text here.
Understanding the interaction of international hard and soft law in a fragmented international law system is increasingly important in a world where international regimes are proliferating, but where there is no overarching legal hierarchy. This Article responds to the existing literature on hard and soft law, which almost exclusively focuses on how they operate as alternatives and complements to each other. First, it shows how international hard- and soft-law instruments often serve as antagonists to each other. Second, it shows how such an antagonistic interaction can affect the very nature of international hard- and soft-law regimes, potentially leading to the hardening of soft-law regimes and the softening of hard-law regimes. Third, it specifies the conditions under which actors are likely to employ hard and soft law as alternatives, complements, or antagonists. The existing literature is not wrong to examine how hard and soft law may be employed as complements and alternatives, but this literature tells only part of the story. This Article provides an analytic framework for understanding the conditions under which states and other actors choose to employ hard and soft law in different ways, emphasizing the role of distributive conflict among countries and their constituencies as the primary factor leading to the use of international hard and soft law as antagonists. The Article elaborates five general hypotheses, whose plausibility is examined with respect to numerous empirical examples involving multiple policy domains.