The issue of consent to international law obligations and liabilities remains both highly complex in theory and extremely relevant in practice. Although the topic has been addressed quite regularly in the form of articles and chapters, there have been, surprisingly for such a central topic, few monographs on consent to international law in general and no edited volume in English language. Re-examining the issue of consent to international law in depth and in the contemporary circumstances of international law is a timely project therefore. The best way to do so in a rich and nuanced way is to give a voice to many authors at the same time, and this is the purpose of this collection of essays. This introduction sets the volume’s stage: first, it clarifies the relevance of the issue and the reasons that led to putting the book together; second, it introduces the main conceptual and normative challenges addressed in the volume and explains what it hopes to achieve; third, it provides some information about how the book is structured; and, finally, it sketches out the content of its successive chapters and their articulation.

The authors begin by observing that most obligations of international law are still regarded as ‘based’ on State consent. There are good reasons for this, especially from a democratic legitimacy perspective. Still, the principle of State consent, even in its qualified version of ‘democratic State’ consent, suffers from important shortcomings that call for correctives. The chapter starts by accounting for the democratic value of State consent in International Organizations (hereafter IOs) before addressing some of its democratic deficits. It then articulates several institutional proposals to correct or, at least, complement the role of equal State consent in the institution, the operation and the control of IOs. The authors develop a non-ideal normative argument for the latter’s political re-institution. That re-institution has to start with the replacement of the principle of equal State consent by that of equal public participation in IOs: this does not only avoid reducing State consent in IOs to State veto or refusal rights, but it also extends the personal scope of those participatory rights to other non-State public institutions.

International responsibility law today is in great need of theorizing or, at least, that is the present volume’s argument. This introduction sets the stage for that argument. It unfolds in four steps: first, it clarifies the reasons that led to putting this collection of essays together and explains what it hopes to achieve; second, it introduces the main theoretical challenges addressed in the volume; third, it provides some information about how the book is organized; and, finally, it sketches out the content of its successive chapters and their articulation.