Frequently asked questions

At the 2010 Review Conference of the Rome Statute of the International Criminal Court States Parties adopted amendments to the Rome Statute on the Crime of Aggression. In November 2010, the Secretary- General of the United Nations circulated the amendments in order to enable States Parties to ratify or accept the amendments. In July 2018, the International Criminal Court’s Jurisdiction over the crime of aggression went into effect. Below are a number of questions and answers that may assist States with ratification of the amendments.

How has the crime of aggression been defined?

The Rome Statute now has a new article 8 bis defining the crime of aggression. In essence, three elements are required. First, the perpetrator must be a leader, i.e. a “person in a position effectively to exercise control over or to direct the political or military action of a State”. Second, the Court must prove that the perpetrator was involved in the planning, preparation, initiation or execution of such a State act of aggression. Third, such a State act must amount to an act of aggression in accordance with the definition contained in new article 8 bis, paragraph 2, and it must, by its character, gravity and scale, constitute a manifest violation of the UN Charter. This implies that only the most serious illegal uses of force between States can be subject to the Court’s jurisdiction. Genuine cases of individual or collective self-defense, as well as action authorized by the Security Council would thus clearly be excluded.

How was the controversial question of the role of the Security Council resolved?

The Security Council plays more than one role with respect to the crime of aggression. First, the Council may serve as a jurisdictional trigger: it may refer a situation to the Court under the Statute’s existing article 13 (b). The new article 15 ter provides that in such a scenario, the Court may in the future also investigate and prosecute charges of aggression, provided there is a reasonable basis to believe a crime of aggression was committed.

Second, the Council serves as the primary jurisdictional filter where the Prosecutor intends to open an investigation proprio motu or on the basis of a State referral. Under new article 15 bis, the Prosecutor must notify the Council so that it can determine if an act of aggression has occurred. If no determination is made within six months, the Prosecutor may only proceed with the authorization of the Pre-Trial Division. Even in that case, however, the Council may suspend proceedings under article 16. This complex system maintains the judicial independence of the Court, in particular since the amendments clearly stipulate – for reasons of due process – that the Court is not bound by a determination of aggression by an outside organ.

How do the amendments on aggression affect non-States Parties to the Statute?

In case of a Security Council referral, the Court may investigate and prosecute the crime of aggression with respect to both Non-States Parties and States Parties, as was already the case in respect of the other three core crimes. In case of proprio motu investigations and State referrals, however, article 15 bis, paragraph 5, excludes jurisdiction with respect to the crime of aggression committed on the territory or by nationals of Non-States Parties.

Article 15 bis allows any State Party to opt-out of the Court’s jurisdiction over the crime of aggression. What are the reasons behind this provision?

The opt-out clause found in new article 15 bis, paragraph 4, has to be seen in the context of the negotiation history. There were fundamental disagreements as to whether the consent of the alleged aggressor State should be a condition for the Court’s exercise of jurisdiction. Positions ranged from a strictly consent-based opt-in approach, whereby the Court could only deal with cases involving an aggressor State that has previously consented to the Court’s jurisdiction, to a strictly victim-centered approach, whereby aggression committed by any State Party and even by a Non-State Party could come under the Court’s jurisdiction, provided that the victim was party to the Statute. The compromise solution was to follow a consent-based approach, based on the fact that States Parties have already accepted the Court’s jurisdiction over the crime of aggression when ratifying the Rome Statute (see article 12(1) of the Statute). Nevertheless, in order to keep the regime truly consent-based, a State Party may at any time, also prior to its own ratification of the amendments, submit an opt-out declaration. This opt-out declaration would however only affect future acts, and not exempt from accountability with respect to acts committed prior to the opt-out declaration. The opt-out system only applies to proprio motu investigations and State referrals, not to Security Council referrals.

What about new States Parties to the Rome Statute? Do they have a choice of ratifying the “old” or the “new” Statute?

Since current States Parties have a choice whether to ratify the amendments or not, new States Parties have the same choice. According to the practice of the UN Office for Legal Affairs, new States Parties would have to indicate clearly in their instrument ratifying the Rome Statute that they also wish to ratify the amendments, otherwise they are deemed to have ratified the “old” Statute – meaning that, as to the crime of aggression, they would be in the same position as States Parties that have not yet ratified the Kampala amendments on aggression.

Do States Parties that ratify the amendments have to incorporate the crime of aggression into their domestic criminal codes?

Given that the principle of complementarity also applies to the crime of aggression, States Parties should ensure that they are able to prosecute the crime of aggression domestically, which may require incorporating the definition of the crime of aggression into a State’s criminal code. The Review Conference clarified that the amendments do not create the right or obligation for any State Party to exercise domestic jurisdiction with respect to an act of aggression committed by another State (Understanding 5). This implies that States Parties should focus their implementing legislation on the crime of aggression committed by its own leaders, though it does not exclude a more expansive jurisdictional regime (e.g. over the crime of aggression committed against the State Party in question). State practice since 2010 shows that none of the implementers has limited its domestic jurisdiction to the crime of aggression by its own leaders. The fundamental principle of territorial jurisdiction, mostly automatically applicable to all crimes included under domestic law, provides for jurisdiction over the crime of aggression committed from and against national territory. There are also States which have established universal jurisdiction over the crime of aggression, e.g. Austria, Cyprus, Georgia, Liechtenstein, Luxembourg, the Netherlands, North Macedonia, Samoa and Slovenia. It should be kept in mind that States which undertake genuine investigation and prosecution of their own nationals for crimes within the jurisdiction of the Court would have priority to try such perpetrators in their own Courts, in which case the ICC would defer to the national prosecution.

What are the policy reasons for which any State would ratify the amendments on the crime of aggression?

Only States Parties that have ratified the amendments will enjoy the broadest possible judicial protection in case of acts of aggression committed against them. Ratifying States also serve the noble goal of promoting a system of international accountability for the most serious instances of illegal use of force between States, including by promoting the definition of the crime of aggression in international law. States Parties, would also avoid the appearance of inconsistency in their respective policies by moving forward with the amendments which they  agreed upon by consensus in Kampala.

What is the status of States Parties that have not yet ratified the Kampala amendments?

There is disagreement as to whether the International Criminal Court can exercise jurisdiction over the crime of aggression involving States Parties that have not yet ratified the Kampala Amendments. The wording and drafting history of Article 15bis(4) of the Rome Statute as well as its systematic comparison to Article 15bis(5) suggest that the ICC can exercise jurisdiction provided that one State has ratified the Kampala Amendments and the aggressor State has not opted out. In contrast, Article 121(5) of the Rome Statute and operative paragraph 2 of the Activating Resolution suggest that all States involved must have ratified the Kampala amendments.

Why can the International Criminal Court not exercise jurisdiction over the crime of aggression allegedly committed against Ukraine?

The International Criminal Court cannot exercise jurisdiction over the crime of aggression allegedly committed against Ukraine due to Article 15 bis paragraph 5 of the ICC Statute. This article excludes the crime of aggression committed on the territory or by the nationals of non-States Parties. Russia is not a State Party, nor is Belarus