Abstract: International lawyers and international relations scholars recognize that international norms change over time. Practices that were once permissible and even “normal” — like slavery, conquest, and wartime plundering — are now prohibited by international rules. Yet though we acknowledge norm change, we are just beginning to understand how and why international rules develop in the ways that they do. This book sketches the primary theoretical perspectives on international norm change, the “legalization” and “transnational activist” approaches, and argues that both are limited by their focus on international rules as outcomes. It then presents the “cycle theory”, in which norm change is continual, a product of the constant interplay among rules, behavior, and disputes. International Norms and Cycles of Change is the natural follow-on to Prohibiting Plunder, testing the cycle theory against ten empirical cases. The cases range from piracy and conquest, to terrorism, slavery, genocide, humanitarian intervention, and the right to democracy. The key finding is that, across long stretches of time and diverse substantive areas, norm change occurs via the cycle dynamic. This book further advances the authors' theoretical approach by arguing that international norms have been shaped by two main currents: sovereignty rules and liberal rules. It includes five cases of sovereignty rules and five of liberal rules in order to reveal the broad cyclic pattern of international change in these two categories of rules.

Keywords: international rules, legalization, transnational activism, cycle theory, empirical cases, sovereignty rules, liberal rules