The Rome Statute for The International Criminal Court (henceforth The Rome Statute) now provides, for the first time, a legally binding definition of the concept of Aggression. The definition is based on the United Nations Charter (henceforth The UN Charter) article 2(4). The Rome Statute is the foundation on which the International Criminal Court (henceforth ICC) can prosecute individuals on crimes of aggression post the events. The United Nations (henceforth UN) has the charter to sustain the peace through acting against the acts of aggression of nations, primarily preventively and based on resolutions by the Security Council. It is interesting to compare the UN Charter and the Rome Statute definition to understand how the concept of aggression is used in international law, both in relations between nations and when individuals shall be held accountable for crimes of aggression. In addition, it’s valuable to understand how the two definitions can impact each other and what the implications might be of similarities and differences.
Hence, this thesis is a comparative study of the concept of aggression in the UN Charter and the Rome Statute. One key conclusion is that there are significant differences in how the aggression is defined in the two documents.
The use and development of the concept Aggression is first accounted for in a historic context as a foundation for the comparative study.
Then, acts of aggression in the UN Charter is thoroughly investigated in three steps. The investigation is carried out in accordance with the Vienna Convention on the Law of Treaties. Firstly, through an interpretation of acts of aggression in accordance with the ordinary meaning of the term in the context of the UN Charter. Secondly through an investigation of the interpretation in relevant UN bodies and in the practice of nations. Thirdly, the definition of the UN General Assembly, resolution 3314, is investigated and criticised as it does not offer a sufficiently clear delimitation of the concept of aggression. Resolution 3314 is, however, of key importance and is used subsequently as an element of comparison. The resolution is also compared with the practice of other UN bodies and the wording of the UN Charter. The thesis proves the that aggression has a vague definition in the UN Charter and that the scope of the concept is different in different UN bodies. However, common to all UN Bodies is to define aggression as the first use of force with a specific aggressive intent in international relations.
Following on UN, the thesis provides a critical investigation of the concept of aggression in the Rome Statute where key differences relative to the UN Charter are accounted for. The Rome Statute lacks specific aggressive intent and such cannot be made part of the interpretation as it would the statutes wording and systematics. Thus, the Rome Statute does not regard a specific aggressive intent aggravating but looks solely to the gravity and scale of the force used. In addition, the Rome Statute includes a threshold with the purpose of excluding a grey zone from the jurisdiction of ICC. Such grey zone does not exist in the UN Charter. The implication of this is that the Rome Statute excludes acts of violence that, among some international lawyers, are regarded to be in a grey zone of jus ad bellum.
The conclusions include a summary of the main differences across the UN Charter, different UN Bodies and the Rome Statute. That leads into a discussion on the potential advantages and drawbacks that come out of these differences plus potential effects of the reciprocal influence. The key element of this discussion is that aggressive intent is missing in the Rome Statute and that the statute’s threshold aims to exclude the legal grey zone in jus ad bellum. The thesis concludes that these differences risk to weaken the prohibition of the use of force in the UN Charter and, as a consequence, that this may favour strong and aggressive nations at the expense of smaller and weaker nations.