This month marked 20 years since the Rome Statue created the International Criminal Court (“ICC”) – the Court responsible for prosecuting international crimes of genocide, crimes against humanity and war crimes. This milestone anniversary was celebrated by extending, with effect from 17 July 2018, the ICC’s prosecutorial remit to include the crime of ‘aggression’. The offence, set out in Article 5 of the Rome Statute, was suspended until a definition of the crime, and conditions for its application, could be agreed by State parties. This was completed at the 2010 Kampala Review Conference and in December 2017 the Assembly of State Parties to the Rome Statute formally adopted the resolution to activate the jurisdiction of the Court over this new crime in July 2018.

What is a crime of aggression?

The new Article 8 bis of the Rome Statute (inserted by resolution RC/Res.6 of 11 June 2010) defines the crime of aggression as “the planning, preparation, initiation or execution, by a person in a position effectively to exercise control over or to direct the political or military action of a State, of an act of aggression which, by its character, gravity and scale, constitutes a manifest violation of the Charter of the United Nations” [Art.8(1) bis Rome Statute]. An “act of aggression” means “the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State, or in any other manner inconsistent with the Charter of the United Nations” [Art.8(2) bis Rome Statute].

The offence can be committed, irrespective of a war being declared, where any of the following acts are committed [Art.8(3) bis Rome Statute]:

(a) The invasion or attack by the armed forces of a State of the territory of another State, or any military occupation, however temporary, resulting from such invasion or attack, or any annexation by the use of force of the territory of another State or part thereof;

(b) Bombardment by the armed forces of a State against the territory of another State or the use of any weapons by a State against the territory of another State;

(c) The blockade of the ports or coasts of a State by the armed forces of another State;

(d) An attack by the armed forces of a State on the land, sea or air forces, or marine and air fleets of another State;

(e) The use of armed forces of one State which are within the territory of another State with the agreement of the receiving State, in contravention of the conditions provided for in the agreement or any extension of their presence in such territory beyond the termination of the agreement;

(f) The action of a State in allowing its territory, which it has placed at the disposal of another State, to be used by that other State for perpetrating an act of aggression against a third State;

(g) The sending by or on behalf of a State of armed bands, groups, irregulars or mercenaries, which carry out acts of armed force against another State of such gravity as to amount to the acts listed above, or its substantial involvement therein”

What can the ICC prosecute?

The offence does not have retrospective effect and the ICC’s prosecutorial power is limited to crimes of aggression committed one year after ratification (or acceptance of the amendments by thirty states parties).

Who can the ICC prosecute?

If a case is initiated by an ICC prosecutor or referred by a State, the Court’s power to prosecute offences of aggression will only apply to crimes committed on the territory, or by nationals, of states which have accepted the Article 8 bis amendment. As the Rome Statute makes it possible for parties to “opt out” at a later date, the scope of the ICC’s power in this arena may change over time. Nonetheless, where a case is referred to the ICC by the UN Security Council the ICC will have jurisdiction to prosecute regardless whether the state has accepted or opted out of the amendment.

As for individuals liable to prosecution, by virtue of Art.8(1) of the Rome Statute the offence applies only to those “in a position effectively to exercise control over or to direct the political or military action of a State”. This means that only those in recognised command positions of the state can be prosecuted.

The UK’s position

The UK has not ratified the amendment yet, stating the need for “greater clarity” before it is able to do so. This means that the ICC will not be able to prosecute UK military or political leaders for alleged offences of aggression unless a referral from the UN Security Council is made to the ICC. However, by virtue of its position within the Security Council, the UK, like the US and Russia, has the power to veto the decision to make such a referral, therefore potentially limiting the effect of Article 8 bis on non-ratifying members of the Council.

The way forward

The fact that a number of states are still yet to ratify the amendment means that it is not a wholesale victory for the ICC. Equally the veto power of the Security Council’s five permanent members remains a strong tool for preventing a prosecution. Nonetheless after a complex, clunky and often criticised history, the activation of the crime of aggression marks an important development in the ICC’s fight against international crime. More than thirty states have already accepted the amendment. For those who are still yet to do so, it may still be a deterrent. No state wants to be accused of abusing their decision not to ratify the amendment in order to carry out crimes of aggression with no repercussions. In short, states will now need to think even more carefully about the gravity and scale of any proposed aggressive action, which can only be a good thing.