In 1946, the International Military Tribunal at Nuremberg expressed the view that aggression “is the supreme international crime differing only from other war crimes in that it contains within itself the accumulated evil of the whole.” In 1998, the offence was included among the core crimes punishable before the International Criminal Court (ICC), whose jurisdiction over it became effective in 2018. And, with the 2022 full-scale invasion of Ukraine, much discussion has centred on the legal responsibility of Russian leaders for aggression. Remarkably, however, in the decades since Nuremberg, or even in the half decade since the ICC’s jurisdiction has been activated, nothing in the literature has considered how the crime should be punished. This paper seeks to fill that gap by considering how the ICC ought to sentence individuals for the illegal use of armed force. It first explores how defendants were sentenced in Europe and Asia for the equivalent offence—crimes against peace—after World War II. It then analyses Part 7 of the Rome Statute—labelled “Penalties”—and its application/interpretation to date. In so doing, the paper posits the existence of a hierarchy among the ICC’s four core crimes. Having regard to the factors relevant to modes of responsibility and sentencing in the applicable legal framework, as well as the ICC’s case law, the paper proposes sentencing consistent with our view of aggression’s high place within the penal hierarchy, given its common, and we believe accurate, characterisation as the poisonous tree that bears the fruit of the other core crimes.

About the Speakers:

Professor Gregory S. Gordon teaches at The Chinese University of Hong Kong Faculty of Law, where he formerly served as Associate Dean (Development and External Affairs) and currently heads the Legal History LLM program. Not long after earning undergraduate and law degrees from Berkeley, he served as an attorney at the United Nations International Criminal Tribunal for Rwanda on the landmark “Media” cases, the first international post-Nuremberg incitement prosecutions of media executives, earning a commendation from U.S. Attorney General Janet Reno. He subsequently worked with the U.S. Department of Justice (DOJ), serving, in sequence, as a street crime, white collar crime, organized crime and then human rights prosecutor (the latter for the Office of Special Investigations, the so-called “Nazi Hunters Unit”). He was detailed by DOJ to Sierra Leone to conduct a post-civil war justice assessment and served as a Special Assistant U.S. Attorney for the District of Columbia. For 2019-20, he was a Visiting Fellow at the European University Institute and the Georgetown University Law Center. Professor Gordon is the author of Atrocity Speech Law: Foundation, Fragmentation, Fruition (Oxford University Press 2017) and of the forthcoming biography of Benjamin Ferencz, titled Nuremberg’s Citizen Prosecutor: Benjamin Ferencz and the Birth of International Justice (University of Virginia Press 2025).

Dr. Daley J. Birkett is a Senior Lecturer at Macquarie Law School. He holds a PhD from the University of Amsterdam as well as LLM (Leiden University) and LLB (Durham University) degrees. Dr. Birkett’s research interests lie in the field of public international law, with a particular focus on the law and practice of international(ized) criminal tribunals and the United Nations Security Council and the jus ad bellum. A prize-winning researcher, he has published his scholarship in prominent periodicals, including the Leiden Journal of International Law, the Journal of International Criminal Justice, the American University International Law Review, and the Chinese Journal of International Law. Dr. Birkett has also (co-)edited and/or contributed chapters to books published by Cambridge University Press, Routledge, and Brill Nijhoff. He has twice served as a Legal Consultant to the United Nations Assistance to the Khmer Rouge Trials, supporting the International Judges of the Supreme Court Chamber of the Extraordinary Chambers in the Courts of Cambodia.