Side Event - “The ICC’s Jurisdiction Over the Crime of Aggression” (hosted by Liechtenstein))

Overview by Isabella Banks, Research Associate PILPG NL


  • The activation of the International Criminal Court’s jurisdiction over the crime of aggression (as of July 2018) is a major development with respect to the rule of law at the international level.

  • Despite evidence of widespread state support, the Court’s jurisdiction over aggression is expanding slowly: only 30% of States Parties have ratified the amendment so far.

  • The panel was united in their calls for continued ratification of the crime of aggression and in their hope that its activation would have a significant deterrent effect.

Hosted by Liechtenstein, this panel discussion focused on the significance and impact of the International Criminal Court’s jurisdiction over the crime of aggression with respect to the prevention of conflict and the protection of human rights. 

Ambassador of Liechtenstein Christian Wenaweser, the moderator and former President of the Assembly of States Parties (ASP), opened the event with a brief summary of major milestones in the ratification process. At the 2010 Kampala Review Conference, States Parties agreed on the elements of the crime of aggression and the conditions under which the Court could exercise jurisdiction. After significant deliberation at last year’s ASP in New York, the States Parties decided by consensus to activate the Court’s jurisdiction over the crime of aggression as of July 17, 2018. Ambassador Wenaweser highlighted the importance of this development with respect to the rule of law at the international level, stating that it “completed the Rome Statute (Article 5) as it was originally drafted 20 years ago.”

Ambassador Wenawesar went on to introduce the three panelists: Jennifer Trahan, a Clinical Professor at the New York University Center for Global Affairs and an eminent expert in the crime of aggression; David Donat Cattin, Secretary General of the Parliamentarians for Global Action and a leading civil society activist with respect to international criminal justice; and Don Ferencz, Convener of the Global Institute on the Crime of Aggression.

Jennifer Trahan began by summarizing the most important elements of the agreed upon definition of aggression (Article 8 bis), noting that they are largely historically derived from the London Charter of the Nuremburg Tribunal. The first paragraph defines the individual “crime of aggression” (specifically, its “planning, preparation, initiation or execution” by a high-level political or military leader), while the second paragraph defines the “act of aggression” that can only be committed by a state. She interpreted the “manifest violation” provision as excluding all debatable cases.

Ms. Trahan went on to describe the crime’s unique jurisdictional regime: non-States Parties are excluded and States Parties may opt out. As for UN Security Council (UNSC) referrals, UNSC statements made about an act of aggression would not be binding on the Court’s findings and therefore would not infringe upon its judicial independence. While the UNSC could in theory refer a specific act of aggression to the Court (as opposed to the broader situation), Ms. Trahan observed that the Rome Statute does not address this explicitly. Ms. Trahan concluded her remarks by emphasizing the significance of the activation and her belief in its potential for “significant deterrence.”

David Donat Cattin, Parliamentarians for Global Action (PGA), stated that the next UNSC referral would “do justice to Nuremburg” 73 years later and echoed Ms. Trahan’s sentiments about deterrence. He provided an overview of ratification progress in various regions of the world, highlighting a number of ratifications in Latin America and the amendment’s almost unanimous adoption by the European Parliament. Acknowledging that Africa would be more difficult, he indicated that the Central African Republic may be the next state to ratify the amendment. He added that states in the process of ratifying the Rome Statute now have the option to accept it as a whole, including the aggression amendment. El Salvador took this step in 2016. Dr. Donat Cattin stressed that the crime of aggression was an important contribution to the normative framework that the international community had built over the past 20 years, and called for sustained efforts in its ratification.

Don Ferencz spoke last, calling attention to the “elephant in the room” that 70 percent of the States Parties and “some major players” had not yet ratified the amendment. Choosing to open the discussion rather than speak at length, Mr. Ferencz called on the audience to consider what message the reluctance of more powerful states to ratify the amendment sends about equality before the law on an international level.

Ambassador Wenaweser then invited questions from the audience.  A Canadian ambassador asked if the panel believed the recent action by the Russian Federation would qualify as an act of aggression. Ms. Trahan replied that the “manifest violation” threshold is high and acknowledged that deterrence was limited for states with veto power on the UNSC.  Ambassador Wenaweser added that while a number of states had stated that it was an act of aggression, it is ultimately for a court of law to decide. Dr. Donat Cattin concurred with Ms. Trahan that the nationality of the alleged aggressor in this case meant that nothing could be done from a jurisdictional point of view. From a definitional perspective, he agreed that the action would be unlikely to meet the “manifest violation” threshold. 

This answer evolved into a broader discussion about the possibility for the act of aggression to be linked to war crimes committed by the aggressor state, which may carry jurisdictional weight before the Court.  The Canadian ambassador in the audience argued that it would be dangerous to create such a link because it would effectively give a carte blancheto the defending state. “A state should be convicted of war crimes regardless of what side it’s on,” she stated. Ms. Trahan agreed. She stated “I think Nuremburg was not wrong when they said [aggression is] the supreme crime of concern – that it encompasses so many other crimes” and said that it was up to the states parties to increase the Court’s jurisdictional reach through ratification and domestic implementation. She further expressed her hope that the UNSC would use “this tool” to limit aggressive war. Dr. Donat Cattin also agreed with the Canadian ambassador, offering the example of the Rwandan Patriotic Front (RPF), which both brought an end to the Rwandan genocide and “may have committed war crimes.” He argued that while the Court’s jurisdiction over the crime of aggression was not automatic as they had hoped it would be, it was a significant first step. He emphasized that the amendment’s practical value was “first of all normative: it sends a very powerful message.”

Mr. Ferencz again weighed in to stress the importance of holding powerful states accountable, and called on the audience to consider how private citizens could be encouraged to come forward with “government secrets” regarding acts of aggression.

Ambassador Wenaweser concluded the discussion by summarizing the contributions of each speaker. Responding to Mr. Ferencz’s comments, he added that the Court’s relatively narrow jurisdiction makes implementation of the crime of aggression at the national level is all the more important.