Global Constitutionalism is devoted to publishing cutting-edge scholarship on the foundations, limitations and principles of public order and their dynamics over time on a global scale. The journal is equally devoted to supporting innovative and interesting ways of presenting scholarship in this interdisciplinary field. In the pages that follow, we introduce one non-conventional way of engaging with these issues by publishing our first ‘Agora’. In ancient Greece, the agora was an area in the city where citizens would engage not only in commercial transactions, but also in public debate over ‘political’ issues. In short, the ancient agora was a location for debating issues and principles of public order – a literal marketplace of ideas – and we seek to revive this meaning by creating a scholarly space for dialogue over current and enduring issues of public order that take place both within and beyond states.

The point of departure for this agora is an argument by Robert Keohane and Julia Morse that contemporary international relations is characterised by contested multilateralism, meaning that states and other actors increasingly challenge existing multilateral institutions through formal and informal multilateral practices designed to promote policy and institutional change.^{Footnote 1} These practices often involve the creation of or use of new or alternative institutions or networks in an effort to disrupt the status quo. Keohane and Morse provide a particularly rich and nuanced account of contested multilateralism; notably, however, they do not address how, if at all, contested multilateralism would impact global constitutionalism.

In an effort to join the issue, we invited a diverse group of influential scholars to address the implications, if any, of contested multilateralism for global constitutionalism from the perspectives of political science, philosophy, and law, respectively. In the pages that follow, we are delighted to present their provocative reflections on this issue, as well as a thoughtful response by Keohane and Morse. Our hope is that these papers will launch a productive dialogue between two strands of literature that have not previously engaged with each other.

We anticipate that this exchange will be the first of many agorae that will appear in this journal. We welcome your reactions to these papers, as well as suggestions for future agorae.

The Editors