'Katselli Proukaki's core conclusion that countermeasures as solidarity measures are permitted by international law is well-founded, is supported by her research in State practice, and should be embraced.''Katselli Proukaki deserves credit for vigorously challenging the ILC approach with good arguments. Her scholarly work contributes greatly to the debate on solidarity measures as one of the still open issues of the law of State responsibility' Achilles Skordas, Solicitor, England and Wales; Visiting Professor, University of Sydney; Visiting Fellow, British Institute of International and Comparative Law