The Complementarity Project


Complementarity is of paramount importance for the operation and impact of international criminal justice. International courts and tribunals are only able to accomplish their mandates and leave a ‘lasting footprint’ on society if they are able to mobilise support for their work and spur genuine justice efforts at the domestic level. Traces of complementarity are replicated in the relationship between the ad hoc tribunals and domestic jurisdiction (Rule 11 bis), the exercise of universal jurisdiction (‘horizontal complementarity’) and the operationalisation of the concept of “Responsibility to Protect.”

One of the dilemmas of complementarity is that many of its theoretical underpinnings and operational features, in international relations and domestic societies, are underdeveloped. The Rome Statute sets out the general contours of the concept in three paragraphs (Article 17), but the existing text leaves a considerable degree of ambiguity and space for creative interpretation. The concept has thus undergone dynamic transformation. The Office of the Prosecutor has developed guidelines and policy principles on complementarity, while other aspects have been clarified by the jurisprudence of the Court in the context of the first situations under investigation. Core notions (‘gravity’, ‘inability’, ‘case’) and key concepts (self-referrals, primacy of domestic jurisdictions, ‘positive complementarity’) are at the heart of judicial and policy debate.

The purpose of the project is to put these developments in perspective. It revisits the conceptual foundations of complementarity, as well as its broader systemic and operational implications. The project is designed to:

– build a bridge between historical understandings of complementarity and its contemporary application;
– offer fresh analysis on core aspects of the interpretation and treatment of complementarity and its implications in international relations;
– provide insider perspectives and critical analysis of the application of complementarity in the first situations under investigation.

In September 2009, the Grotius Centre held an interdisciplinary research conference on the theme of complementarity at the Peace Palace and Campus The Hague. The conference brought together Hague officials, researchers, members of the diplomatic community and NGOs to discuss the relationship between the ICC and domestic jurisdictions. Speakers included Mr. Luis Moreno-Ocampo (Prosecutor, ICC), Mrs. Silvana Arbia (Registrar, ICC), Mr. David Tolbert (Registrar, Special Tribunal for Lebanon ), Hon. Freddie Ruhindi (Minister of State for Justice and Constitutional Affairs, Uganda ) and Justice Dan Akiiki (War Crimes Division, Uganda). A summary and report of the proceedings may be found here and here. In 2011, an edited volume based on this research, The International Criminal Court and Complementarity: From Theory to Practice, was published with Cambridge University Press.

The project is thematically linked to NWO funded research of the Grotius Centre on ‘Post-Conflict Justice and Local Ownership.’

Project Contributors

Luis Moreno-Ocampo; Juan E. Mendez ; Silvana Arbia; Mauro Politi; William A. Schabas; Christoph Burchard ; Mark A. Drumbl; Payam Akhavan; Michael A. Newton; William W. Burke-White; Frédéric Mégret ; Héctor Olásolo & Enrique Carnero Rojo; Rod Rastan ; Darryl Robinson; Jo Stigen ; Ben Batros ; Ignaz Stegmiller; Megan A. Fairlie & Joseph Powderly ; Harmen van der Wilt; Jann K. Kleffner; Roger S. Clark; Gregory Gordon; Federica Gioia; Olympia Bekou ; Cedric Ryngaert; David Tolbert & Aleksandar Kontić; Fidelma Donlon; Tarik Abdulhak; Paul F. Seils; Christopher K. Hall; Kai Ambos; Robert Cryer; Sarah Nouwen; Marieke Wierda & Michael Otim; Phil Clark; Marlies Glasius; Morten Bergsmo, Olympia Bekou & Annika Jones and Christine Alai and Njonjo Mue.