My current research explores the ways in which international law shapes the authority of sovereign states and changes their relationship to their own citizens and to other states. My first book entitled Divided Sovereignty: International Institutions and the Limits of State Authority was published by Oxford University Press in 2015. Divided Sovereignty explores new institutional solutions to the old question of how to constrain states when they commit severe abuses against their own citizens. I defend universal, principled limits on state authority based on jus cogens norms, a special category of norms in international law that prohibit violations of basic human rights.
My new book project, tentatively entitled Reasons for International Rules: Dynamic Coordination, State Consent, and Binding Law, examines under what conditions international law is compatible with the sovereignty claims of constitutional democracies. Recent political events in the UK and the US have revealed a deep scepticism of processes that take politics beyond national boundaries, such as European or international law. This scepticism is not new. Informed by existing arguments made by realists about the clash between international law and national interest, the most common form of this scepticism is that international law actively undermines the authority of constitutional democracies by substituting its judgments for the judgment of self-governing political communities. My book will show that the reasons we have to defend the establishment of legal institutions are the same as inside and across political communities and that international law can be developed in a manner that is compatible with the authority of constitutional democracies.