At its 80th biennial conference, the International Law Association adopted the Lisbon Conclusions and Recommendations on Positive Complementarity.
Serving as Rapporteur to the Committee of 40 experts on complementarity for six years, Sarah Nouwen, Professor of Public International Law, drafted the report, including its conclusions and recommendations.
Positive complementarity is a policy that aims to enhance the capacity and willingness of states to investigate and prosecute international crimes, specifically war crimes, crimes against humanity, genocide and aggression.
The report has identified over twenty potential obstacles to such proceedings at the national level and has identified concrete steps that states, international organisations and scholars can take to help address such obstacles. The recommendations also tackle existing tensions over terminology and strike a balance between international concern and national ownership.