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Shared Responsibility in International Law

SHARES (2010-2015)

The SHARES Project examined an unexplored and largely unrecognised problem: the allocation of international responsibility among multiple states and other actors. It uncovered the nature and extent of the problem of sharing responsibility in an increasingly interdependent and heterogeneous international legal order.

The Project produced output, offering new concepts, principles and perspectives for understanding how the international legal order may deal with shared responsibility. SHARES was funded by a European Research Council Advanced Grant of 2.1 million euro, obtained in 2010 by Professor André Nollkaemper. The Project ran until the end of 2015.

SHARES Animation Movie
SHARES Animation Movie


  • André Nollkaemper
  • Jean d’Aspremont
  • Maarten den Heijer
  • Dov Jacobs
  • Ilias Plakokefalos
  • Christiane Ahlborn
  • Kristen Boon
  • Bérénice Boutin
  • Kathryn Greenman
  • Nienke van der Have
  • Gleider Hernández
  • Emma Irving
  • Erik Kok
  • Francesco Messineo
  • Nataša Nedeski
  • Isabelle Swerissen
  • Jessica Schechinger
  • Annemarieke Vermeer-Künzli

Selected Output

For a longer list of the project output, see:


Close to a hundred blogs were written as part of the project, which are available on the following website:


  • Nollkaemper, A., d’ Aspremont, J., Ahlborn, C., Boutin, B., Nedeski, N., Plakokefalos, I., & Jacobs, D. (2020). Guiding Principles on Shared Responsibility in International Law. European Journal of International Law, 31(1), 15-72.
  • Nollkaemper, A. (2018). The duality of shared responsibility. Contemporary Politics, 24(5), 524-544.
  • Plakokefalos, I. (2015). Causation in the Law of State Responsibility and the Problem of Overdetermination: In Search of Clarity. European Journal of International Law, 26(2), 471-492.
  • D’ Aspremont, J., Nollkaemper, A., Plakokefalos, I., & Ryngaert, C. (2015). Sharing Responsibility Between Non-State Actors and States in International Law: Introduction. Netherlands International Law Review, 62, 49-67.
  • Nollkaemper, A., & Jacobs, D. (2013). Shared Responsibility in International Law: A Conceptual Framework. Michigan Journal of International Law, 34(2), 359-438.
  • Nollkaemper, A. (2012). International Adjudication of Global Public Goods: The Intersection of Substance and Procedure. European Journal of International Law, 23(3), 769-791.


  • Nedeski, N. Shared Obligations in International Law. Cambridge: Cambridge University Press, 2022.
  • Nollkaemper, A. & Plakokefalos, I. (Eds.), Principles of shared responsibility in international law: an appraisal of the state of the art. Cambridge: Cambridge University Press, 2017.
  • Nollkaemper, A. & Jacobs, D. (Eds.), Distribution of responsibilities in international law. Cambridge: Cambridge University Press, 2015.
  • Nollkaemper, A. & Plakokefalos, I. (Eds.), The Practice of Shared Responsibility in International Law. Cambridge: Cambridge University Press, 2014.