Civil Society Calls for the Reform of the ICC’s Jurisdiction over the Crime of Aggression: Towards the July 2025 Review of the Kampala Amendments

[Isabelle Haßfurther is a senior legal advisor in the International Crimes and Accountability program at the European Center for Constitutional and Human Rights (ECCHR). ECCHR has been supporting the reform process and is one of over 80 co-signatories of the Joint Civil Society Statement calling for harmonization of the ICC’s jurisdiction over the crime of aggression with jurisdiction over the other three core crimes.]

In less than two weeks, during a Special Session scheduled to take place from 7 to 9 July 2025, states parties of the International Criminal Court [ICC] will be presented with a unique opportunity to finally remedy a glaring accountability gap in international criminal law: namely the one resulting from the ICC’s fragmented jurisdiction over the crime of aggression.

In light of a geopolitical climate in which the international legal order as a whole and particularly the prohibition of the use of force as one of its corner stones are increasingly challenged, awareness has been rising for the need to ensure better protection from and deterrence of the commission of aggression. The current framework of international criminal law is ill-prepared to do so. It therefore stands to be hoped that ICC states parties will unite behind the goal of defending international peace and security and adopt an amendment harmonizing the Court’s jurisdiction over the crime of aggression with the other core crimes. 

A convincing proposal to that effect was tabled in April. It mirrors recommendations based on extensive scholarly research and debate, illustrating that the reform is legally feasible and ultimately only a question of political will. Against this background, over 80 civil society organizations from all around the world are calling on states parties not to let this opportunity go by but to seize it and work towards ending impunity for the crime of aggression. 

Reform of the ICC’s Jurisdiction over the Crime of Aggression – Remedying a Double Standard in International Law

The upcoming Special Session, planned to take place in New York in July 2025, was already foreseen in 2010. When ICC states parties consensually adopted the ‘Amendments to the Rome Statute of the International Criminal Court on the crime of aggression’ in Kampala, Uganda, [Kampala Amendments] after years of negotiation, they decided “to review the amendments of the aggression seven years after the beginning of the Court’s exercise of jurisdiction” (Resolution RC/Res.6(4)) and hence seven years after the Kampala Amendments’ activation in 2018. 

This review was part of the hard-won compromise found in Kampala: A large number of states parties favored a jurisdictional framework aligned with the one for genocide, crimes against humanity and war crimes as enshrined in Art. 12 (2) and (3) of the Rome Statute (see Kreß/von Holtzendorff, p. 1195), meaning that the ICC would have had jurisdiction concerning state referrals or proprio motu investigations whenever the state whose nationals committed the crime or the state on whose territory it was committed is an ICC state party or accepts jurisdiction ad hoc. This includes acts committed by nationals of non-states parties on the territory of a state party. The opponents of this harmonized framework – including France, the UK and the US – however, ultimately prevented it from being adopted. The result can be found in Art. 15bis (4) and (5), which establish a full exception for crimes committed on non-states parties’ territory or by their nationals and the possibility of opting out of the ICC’s jurisdiction for states parties. In these cases, accountability can only be ensured through a referral by the UN Security Council (Art. 15ter of the Rome Statute) – a way likely unavailable regarding accountability of its permanent members with veto power or their allies.

Neither states whose territory is attacked in a war of aggression, nor third states can fully close these jurisdictional gaps. The reason is the personal immunity of incumbent head of state, head of government and foreign minister. The crime of aggression constitutes a leadership crime, but, due to this immunity, the highest ranks of said leadership which are usually “in a position effectively to exercise control over or direct the political or military action of a state” as required by Art. 8bis of the Rome Statute – and thus the principal suspects of crimes of aggression – can only be prosecuted after their time in office. To remedy this situation through Special Tribunals may be necessary and understandable in the short-term but does not constitute a convincing long-term solution. A crucial precondition of the legitimacy of international law and international criminal justice is the equal application of the norms the international community has agreed to uphold and, correspondingly, to ensure indiscriminate accountability without double standards when these norms are violated.

The Urgent Need for Reform and Civil Society’s Call to Seize the Opportunity

It is therefore imperative to work towards a jurisdictional framework for the crime of aggression as universal as possible which covers all the states that seek protection under the Rome Statute. When the Rome Statute and the Kampala Amendments were adopted in 1998 and 2010 and even up until more recently, wars of aggression were perceived as an increasingly unlikely scenario with international armed conflicts and annexations seemingly on the decline (see Bassiouni, p. 49). The past years and even months have, however, proven this assumption wrong. What we have witnessed are more and more blunt threats with as well as the open use of aggressive warfare and other acts of aggression.

ICC states parties must back the prohibition of aggression as corner stone of the international legal order now more than ever. This norm, which states have long agreed to as so fundamental that it enjoys non-derogatory status, is absolutely crucial for the protection of a law-based order by contrast to an international system in which the stronger state simply takes what it wants. What is more, beyond the protection of state sovereignty, peace is also intricately linked to the realization of human rights. As pointed out by UN High Commissioner for Human Rights, Volker Türk, “the right to peace is the mother of all human rights. Without the right to peace, all other rights are squashed.” With regard to the right to life as enshrined in the International Covenant on Civil and Political Rights, the UN Human Rights Committee has been very clear on the implications of aggression: “States parties engaged in acts of aggression […] resulting in deprivation of life, violate ipso facto article 6 of the Covenant. At the same time, all States are reminded of their responsibility as members of the international community to protect lives and to oppose widespread or systematic attacks on the right to life, including acts of aggression.” It is hence in the interest of both the populations subjected to aggressive warfare as well as the international community as a whole to improve the legal framework.

One way to do so is by strengthening the deterrent effect of accountability for recourse to aggression. The crime of aggression as one of the core crimes criminalizes manifest violations of the prohibition of the use of force. If wars of aggression remain without tangible consequences for the aggressors, they will certainly become (or remain) a recurring phenomenon. As emphasized by former Nuremberg prosecutor Benjamin Ferencz, immunity from prosecution certainly does not dissuade “illegal war-making, but rather encourages it”. The latest geopolitical developments prove him right. Furthermore, the prosecution of the crime of aggression is crucial to fully account for the harm caused to both soldiers fighting in wars of aggression as well as to civilians killed in ‘proportionate’ attacks. While these cases may not constitute war crimes, they are part of the illegal aggression.

Against this background, civil society has accompanied and pushed for the reform. So far, over 80 civil society organizations [CSOs] from all around the world have co-signed a Joint Civil Society Statement which urges ICC states parties not to miss this opportunity to amend the ICC’s jurisdiction. Since the adoption of the Kampala Amendments, various leading academics on the crime of aggression have pointed out the shortcomings of the jurisdictional framework and proposed concrete solutions to address them (see Kreß; McDougall; Reisinger Coracini; Trahan to name a few). Similarly, CSOs such as Parliamentarians for Global Action and the Global Institute for the Prevention of Aggression [GIPA] – a group of around 50 experts on international criminal law and the crime of aggression – have made proposals on what the reform can look like. What all of them agree on is that the amendments are legally possible. All that is needed now are the necessary political majorities.

Welcome Momentum Towards Reform and a Sound Proposal on the Table

And fortunately, it seems that the willingness to tackle the reform has emerged, at least on the part of a large number of states parties. The discussion around the need to close accountability gaps for the crime of aggression in a consistent manner to prevent double standards initially picked up speed after Russia’s full-scale invasion in Ukraine (see already here). In the past two years, a ‘Group of Friends’ of approximately 40 states parties has convened and facilitated exchanges between state representatives, academics and CSOs on the reform (see for example here and here). Moreover, the CSO Africa Legal Aid held a first retreat of 28 African ICC states parties in October 2024 to discuss a “crime of aggression regime that is both fair and legitimate”. A follow-up retreat took place in May 2025 “to solidify Africa’s stance on a crime of aggression regime devoid of inequity and double standards”. During the Assembly of States Parties both in 2023 and 2024, states affirmed their intention to undertake the review upcoming in July by consensus (ICC-ASP/22/Res.3(157); ICC-ASP/23/Res.1(161)). Since then, the ICC’s Working Group on Amendments has held regular meetings to prepare the Special Session. Moreover, independently of the reform, further states parties have recently decided to finally accept or ratify the Kampala Amendments (namely Ukraine, Denmark and Timor Leste).

On 4 April 2025, Costa Rica, Germany, Sierra Leone, Slovenia and Vanuatu submitted the text of a proposed amendment to be considered for adoption at the Special Session. It foresees to replace the text currently contained in Art. 15bis (4) and (5) with one mirroring the jurisdictional regime of Art. 12, thereby ensuring harmonization of the Court’s jurisdiction over all four core crimes. The proposal coincides with the well-reasoned approach presented by the international criminal law experts of GIPA (for an in-depth explanation why this specific wording should be chosen see GIPA’s explanatory memorandum here, paras 11 ff.). 

To adopt the proposed amendment at the Special Session, a two-thirds majority of states parties will be necessary, currently amounting to 83 states. With a view to the number of states which have already been outspokenly in favor of the reform or at least open to discussions on the reform process, this seems well within reach. After the adoption, states parties will have to demonstrate their support for closing the accountability gap a second time through ratifying the new amendment for it to enter into force. Some authors are arguing that this second step necessarily calls for a majority of seven-eighths of the states parties in application of Art. 121(4) of the Rome Statute and are accordingly skeptical about the prospects of success (see Heller; expressing concern about uncertainty in this regard and therefore suggesting to include a clarification on the applicable procedure in an amendment is Einarsen). There is, however, already a plausible procedural alternative: Art. 121(5) S. 1 of the Rome Statute, which allows every state party to independently take the decision to ratify the amendment and would thus contribute to a swift entry into force for all states interested in better protection from crimes of aggression. Given that the ratification of the Kampala Amendments was similarly governed by this provision, states could now choose the same procedural road for the amendment of the Kampala Amendments “for reasons of consistency” (see GIPA, para 21).

Conclusion

During the Special Session, states parties will be presented with a unique opportunity to strengthen the international legal order and protect their populations from aggression. With the necessary political will, they can harmonize the ICC’s jurisdiction over the crime of aggression with that over the other core crimes. There are no legal or political arguments supporting the current fragmented framework, allowing for the commission of one of the core crimes to go unanswered. Leading experts have shown that the reform is legally feasible, a sound proposal is on the table. Civil society organizations from all around the world therefore call on states parties to join forces and work towards finally closing this accountability gap in the interest of international peace and of those living with the dire consequences of crimes of aggression.