Aggression is a crime in international law. It means a state uses armed force against another state. It is a crime for leaders. The International Criminal Court (ICC) can prosecute it. But this power is new and has limits. This essay explains the crime of aggression. It looks at how it is defined and how it can be prosecuted by the ICC.
Defining Aggression
The Rome Statute is the treaty for the ICC. It listed aggression as a crime from the start (Rome Statute of the International Criminal Court 1998, Art 5(1)(d)). But it did not define it. States could not agree on a definition. In 2010, states met in Kampala, Uganda. At this Review Conference, they finally agreed on a definition. This definition is now in Article 8 *bis* of the Rome Statute.
The definition has two parts. First, there must be an ‘act of aggression’ by a state. This is the use of armed force against the sovereignty, territorial integrity or political independence of another state. This idea comes from a United Nations General Assembly Resolution from 1974 (UNGA Res 3314). Examples include invasion, military occupation, bombing, or a blockade of ports. For the ICC to act, the violation of the UN Charter must be ‘manifest’ in its character, gravity and scale.
Second, the crime of aggression is a leadership crime. Only a person in a position to ‘exercise control over or to direct the political or military action of a State’ can be prosecuted (Rome Statute of the International Criminal Court 1998, Art 8 *bis*(1)). This means it applies to high-level political or military leaders. It is not a crime for ordinary soldiers.
Prosecuting Aggression
The ICC cannot prosecute aggression easily. There are special rules. These rules are in Article 15 *bis* and 15 *ter* of the Rome Statute. The court’s jurisdiction over the crime was activated on 17 July 2018.
There are two main ways a case can begin. The first is a referral from the UN Security Council. If the Security Council refers a situation, the ICC Prosecutor can investigate acts of aggression. This can include aggression by states that are not parties to the Rome Statute.
The second way is for the ICC Prosecutor to start an investigation on their own initiative (*proprio motu*). This path is much more restricted. The Prosecutor can only investigate the crime of aggression if it is committed by a State Party that has ratified or accepted the amendments on aggression. Furthermore, the Security Council can be asked to determine if an act of aggression has occurred, and if it does not do so within six months, the Prosecutor may proceed, but only with authorisation from the court’s Pre-Trial Division.
Problems with the Crime
The crime of aggression has problems. The biggest problem is politics. The UN Security Council has five permanent members (the P5). These are China, France, Russia, the United Kingdom, and the United States. They have a veto power. They can block a referral to the ICC. It is very unlikely that the Security Council would ever refer a situation involving one of the P5 states or one of their close allies (Akande, 2012).
This creates a problem of selectivity. The crime of aggression might only be used against leaders of weaker states. Leaders of powerful states seem protected from prosecution. This makes some people think that international criminal justice is not applied equally to everyone. Another problem is that few states have ratified the Kampala amendments. This seriously limits the ICC’s ability to act without a Security Council referral.
Conclusion
The crime of aggression is now a defined crime under the Rome Statute. This is an important development. At the Nuremberg trials after World War Two, it was called the ‘supreme international crime’. However, there are serious limits on its prosecution. The jurisdiction of the ICC is complex and depends heavily on the political decisions of the UN Security Council. The power of the P5 is a major obstacle to accountability. Therefore, while the crime exists on paper, holding leaders accountable for planning and waging aggressive war will remain very difficult in practice.
References
- Akande, D. (2012) ‘The Crime of Aggression: From the London Charter to the Rome Statute and Beyond’, in Schabas, W. A. and Bernaz, N. (eds.) Routledge Handbook of International Criminal Law. Abingdon: Routledge.
- Rome Statute of the International Criminal Court (1998) UN Doc A/CONF.183/9.
- United Nations General Assembly (1974) Resolution 3314 (XXIX), Definition of Aggression. A/RES/3314 (XXIX).
