The International Criminal Court and Prosecution of Crimes of Aggression

Individuals in leadership positions have been considered to be influential and capable of inciting the commission of crime of aggression under the international law, and therefore their inclusion in criminalisation and prosecution of crime of aggression has been deemed essential. It has been argued that the ICC lacks effectiveness in prosecuting crimes of aggression by individuals, with Mary Ellen noting that despite the Rome Statute having included a detailed provision on the crime of aggression, the likelihood of individuals being prosecuted for this crime “appears minute” as the “procedure for the entry into force of the aggression amendments is byzantine, and the substantive provision leaves experts unclear as to what the prosecutable crime even is. This essay critically discusses the jurisdiction of the International Criminal Court (ICC) to prosecute individuals for crimes of aggression and probes the question as to whether it is likely to be successful in deterring individuals from committing the crime of aggression.

The ICC was established under the Rome Statute of the International Criminal Court and it has worldwide jurisdiction. The Rome Statute is important because it established the ICC and also international criminal law. The jurisdiction of the ICC is to prosecute serious crimes against humanity and gross violation of human rights and also deterring of commission of such crimes. Article 25 provides that the jurisdiction of the ICC is limited to ‘natural persons’. Thus, the ICC does in general have the jurisdiction to prosecute individuals.

The Nuremberg Tribunal had stated that the crime of aggression is the highest form of crime in international domain. However, the question is whether the ICC has been able to deter the commission of these crimes. The ICC has failed to deter the commission of serious crimes, especially by individuals because of some gaps in the institution itself. With respect to the deterrence of individuals from crimes of aggression, the gaps relate to the lack of a clear definition of the crime of aggression; lack of clarity of the elements constituting the crime of aggression; and lack of consensus on whether the ICC is appropriate forum for prosecuting crimes of aggression. During the 2010 Kampala conference itself, an argument was made that the ICC is not the appropriate forum for prosecuting individuals for the crime of aggression.

1. Philip Kirsch and John T Holmes, ‘The Rome conference on an International Criminal Court: the negotiating process’ (1999) 93(1) American Journal of International Law 2.
2. Mary Ellen O'Connell and Mirakmal Miyazmatov, ‘What is Aggression-Comparing the Jus de Bellum and the ICC Statute’ (2012) 10 J. Int'l Crim. Just. 189, p. 191.
3. Rome Statute of the International Criminal Court, 2187 UNTS 90 (17th July 1998).
4. R Cryer, H Friedman, D Robinson, E Wilmshurst, An introduction to international criminal law and procedure (Cambridge University Press 2010).
5. Mauro Politi, The Rome Statute of the International Criminal Court: a challenge to impunity (Routledge 2017).
6. Benjamin B Ferencz, ‘Ending Impunity for the Crime of Aggression’ (2009) 41 Case Western Reserve Journal of International Law 281.
7. Roger S Clark, ‘Negotiating provisions defining the crime of aggression, its elements and the conditions for ICC exercise of jurisdiction over it’ (2009) 20(4) European Journal of International Law 1103, p.1105.
8. Harold Hongju Koh, ‘Statement Regarding Crime of Aggression at the Resumed Eighth Session of the Assembly of States Parties of the International Criminal Court’ (23rd March 2010) accessed

Aggression was not clearly defined in the Rome Statute, Part 2, Article 5(1) which defines the crimes that ICC can prosecute, these being war crimes, crimes against humanity and genocide. The Rome Statute did not include or define crime of aggression, but it tasked the Preparatory Commission to make proposals to define aggression and determine its elements and identify the conditions to hear and prosecute crimes of aggression. Even the customary international law does not provide a definition of the crime which can be used by the ICC to prosecute individuals for crimes of aggression. In order for ICC to prosecute individuals for the crime, it has to be defined in precise terms.

Clark has noted that there have been problems with respect to defining aggression in the context of the ICC because it is usually associated with persons in leadership positions making it difficult to build consensus amongst states to agree on the definition. To be sure, the ICC Special Working Group on Crime of Aggression did admit to the difficulty of formulating a definition of aggression in context of individuals in leadership positions. Therefore, one of the major difficulties that ICC faces is related to the lack of clear conceptualisation of crime of aggression and the lack of clear linkage between individuals and the crime as constituents of the crime. The Kampala Conference 2010 proposed Article 8bis with an emphasis on ‘act of aggression’ being related to state responsibility, and ‘crime of aggression’ being related to the individual. This was adopted as amendment to the Rome Statute through Resolution RC Res/6, which defines aggression as “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. Therefore, a clear linkage to individual and crime of aggression is made out.

Article 8bis is different from how aggression is generally defined in international law. Aggression is defined by the UN General Assembly as 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.” The definition of aggression does not mention individual as the perpetrator of the crime, but clearly identifies the crime of aggression with the state as the aggressor. The ICC has been provided with the jurisdiction to prosecute individuals for international crimes, including aggression as per the provisions of the Rome Statute; and now there is a definition of the crime through the amendment, but it still remains ineffective in prosecuting individuals.

1. Final Act of the UN Diplomatic Conference of Plenipotentiaries on the Establishment of an International Criminal Court, Annex I, Resolution F (UN Doc A/CONF.183/10, 1998).
2. Bing Bing Jia, ‘The crime of aggression as custom and the mechanisms for determining acts of aggression’ (2015) 109(3) American Journal of International Law 569.
3. Ibid.
4. Roger S Clark, ‘Negotiating provisions defining the crime of aggression, its elements and the conditions for ICC exercise of jurisdiction over it’ (2009) 20(4) European Journal of International Law 1103, p.1110.
5. Philip Kirsch and John T Holmes, ‘The Rome conference on an International Criminal Court: the negotiating process’ (1999) 93(1) American Journal of International Law 2.
6. Roger S Clark, ‘Negotiating provisions defining the crime of aggression, its elements and the conditions for ICC exercise of jurisdiction over it’ (2009) 20(4) European Journal of International Law 1103, p.1105.
7. Douglas Guilfoyle, International Criminal Law (Oxford University Press 2016).
8. UN General Assembly Resolution 3314 (XXIX) (Definition of Aggression) adopted by the United Nations General Assembly on December 14, 1974.

Although the ICC is unique in that it is the first permanent international court with jurisdiction to prosecute persons accused of international crimes, the difficulty for ICC comes from the traditional notions of criminal as the domain of municipal law, with individuals being subject to the criminal law of the state. This creates a tension between international law and municipal law, which is also visible in the way that many states question the propriety of the ICC having jurisdiction to prosecute individuals for crime of aggression. This tension manifested itself in the problems related to the obtaining of consensus on the definition of the crime of aggression for the purpose of the Rome Statute and therefore, institutional weaknesses for the ICC to be effective in prosecuting individuals for the crimes of aggression. Eventually, these institutional weaknesses have led to the ineffectiveness of ICC in context of prosecution of individuals for crimes of aggression.

Moreover, criminal law is generally considered to be consensual in nature, with the consensus of the society being central to the ways in which crimes are defined and punishments prescribed, which is something that comes from the international community as far as international crimes are concerned. With regard to the definition of the crime of aggression, such international consensus has deluded the international law and this is more relevant after the Kosovo, Afghanistan, Iraq, and Georgia wars, due to which ICC has often been seriously constrained to act even in crimes of aggression. In these events, states have used the argument of humanitarian intervention as a justification for use of force and there has been a lack of consensus on where such use of force is justified. If the international community does not find consensus in how to define use of force and the justifications for it then, it becomes “almost impossible for the [International Criminal] Court to apply the Working Group definition to the ‘hard cases’ of international life.” It has been argued that the Kampala proposal defined aggression solely a leadership crime, and this does not apply to soldiers making ICC jurisdiction incomplete in the matter. Another problem with the Kampala proposal is that only certain acts of aggression, which are defined as ‘grave and manifest in their violation of the UN Charter’ are within the definition of the crimes of aggression.

1. Rome Statute of the International Criminal Court, Article 5.
2. Carsten Stahn, ‘Complementarity, amnesties, and alternative forms of justice: some interpretative guidelines for the International Criminal Court’ (2005) 3(3) Journal of International Criminal Justice 695.
3. Ibid.
4. Harold Hongju Koh, ‘Statement Regarding Crime of Aggression at the Resumed Eighth Session of the Assembly of States Parties of the International Criminal Court’ (23rd March 2010) accessed
5. Andreas Paulus, ‘Second thoughts on the crime of aggression’ (2009) 20(4) European journal of international law 1117, p. 1122.
6. Ibid.
7. Nußberger, ‘The War between Russia and Georgia – Consequences and Unresolved Questions’ (2009) 1 Göttingen J Int’l L 341, p.345.
8. Andreas Paulus, ‘Second thoughts on the crime of aggression’ (2009) 20(4) European journal of international law 1117, p.1124.
9. Andreas Paulus, ‘Second thoughts on the crime of aggression’ (2009) 20(4) European journal of international law 1117, p.1120.
10. Ibid, p.1121.

The ICC’s effective exercise of jurisdiction in case of crimes of aggression also depends on the clarity with which the conditions for prosecution of crimes of aggression are defined; these conditions were reached at during the Kampala Conference and were formulated in Article 15bis. There was a lack of consensus that can be made out in the alternatives provided in Article 15bis. Weisbord has linked the ICC’s inability to effectively prosecute crimes of aggression by individuals to these lack of consensus or agreement on the conditions necessary for the exercise of ICC jurisdiction, arguing that ICC lacks an effective framework in this area. One of the areas where the problem of lack of clarity on conditions is relevant is the lack of a narrower standard for mens rea. Individuals cannot be prosecuted effectively for crimes of aggression unless the mental aspects of individual accountability are clearly identified. The element of mens rea is defined in Article 30 of the Rome Statute as including intention and knowledge as material elements of this crime. The Kampala conference has on the other hand focused on the definition of mens rea as the requirement of proof of the perpetrator’s knowledge based on the “factual circumstances that establish the inconsistency” between their acts and the UN Charter. The problem with this approach is that the ICC while prosecuting an individual for crimes of aggression will be required to establish defendant’s factual knowledge on how their acts are inconsistent with the UN charter. The ICC is being asked to establish the perpetrator’s knowledge, which is difficult to establish.

From a more political aspect of how crimes of aggression by individuals are likely to be prosecuted, it may be noted that there is a lack of consensus on how far the UN Security Council is involved in the process; the permanent members of the Security Council have demanded that the Security Council should have the power to determine whether an act of aggression has taken place in order for the ICC to prosecute such a crime; but there are justifiable concerns on the use of veto to shield powerful individuals from prosecution. Read with the difficulty of establishing “factual circumstances that establish the inconsistency” between the acts and the UN Charter, it can be said that there are justifications that can be given to deny such factual circumstances establishing inconsistency and if the matter is left to the Security Council, there can be steps taken to shield individual leaders from prosecution even by a single veto of a permanent member.

An important point to note is that the ICC could find it exceedingly difficult to prosecute individuals for crimes of aggression when the scope of justified use of force (for humanitarian purposes for instance) is getting wider and gaining more acceptance in international law. Individuals can argue that their actions, even though technically aggression in international law, are justified on humanitarian grounds and intended to prevent more serious and grave human rights violations. Therefore, even if the ICC is able to establish its jurisdiction in a specific case involving a crime of aggression, it is possible that the individual would be able to justify the aggression on grounds of humanitarian intervention or even other grounds like self-defence. An example can be seen in American intervention in Syria, and its justification on the basis of self-defence against terrorists, which goes beyond the Caroline principle, but is increasingly justified in state practice. Therefore, complicating and challenging the ICC’s task in prosecuting individuals for crimes of aggression is the expanding scope of use of force with individuals likely to escape prosecution for crimes of aggression because they are able to justify the actions based on the defences available to them and also by taking advantage of the gaps in the institutional framework of the ICC, which ae visible in the lack of clarity on the definition of crimes of aggression as well as the problems with the procedure discussed earlier in this essay.

1. Roger S Clark, ‘Negotiating provisions defining the crime of aggression, its elements and the conditions for ICC exercise of jurisdiction over it’ (2009) 20(4) European Journal of International Law 1103, p.1106.
2. Ibid.
3. Noah Weisbord, ‘The mens rea of the Crime of Aggression’ (2013) 12 Wash. U. Global Stud. L. Rev. 487.
4. Mary Ellen O'Connell and Mirakmal Miyazmatov, ‘What is Aggression-Comparing the Jus de Bellum and the ICC Statute’ (2012) 10 J. Int'l Crim. Just. 189, p.205.
5. Ibid.
6. Ibid.
7. Amendments to the Elements of Crimes, Annex II, RC/Res. 6, 11 June 2010.
8. Jon Heller, ‘Retreat from Nuremberg: the leadership requirement in the crime of aggression’ (2007) 18(3) European Journal of International Law 477.
9. Muhammad A Shukri, ‘Will Aggressors Ever be Tried before the ICC’, in Mauro Politi, The International Criminal Court and the Crime of Aggression (Routledge 2017).

To conclude, the jurisdiction of ICC with respect to crimes of aggression suffers from ineffectiveness due to the institutional gaps in the ICC’s framework related to this crime. The ICC has jurisdiction to prosecute crimes of aggression but institutional loopholes have come in the way of its effective exercise. Article 8bis definition is suffers from the lack of consensus on the leadership requirement. There are also problems related to mens rea required for the crimes of aggression as this would be difficult to establish. Finally, the expanding scope of defences against use of force makes it likely that individuals will be able to justify their actions based on their motivations for the aggression and link it to justified grounds like humanitarian intervention or self-defence.

1. E Leclerc-Gagne and M Byers, ‘A Question of Intent: The Crime of Aggression and Unilateral Humanitarian Intervention’ (2009) 41 Case Western Reserve Journal of International Law 379.
2. RY Jennings, ‘The Caroline and McLeod Cases’ (1938) 32 American Journal of International Law 82.
3. Michael P. Scharf, ‘How the War Against ISIS Changed International Law’ (2016) 48 Case W. Res. J. Int'l L. 16.

Books

Cryer R, Friedman H, Robinson D, Wilmshurst, E An introduction to international criminal law and procedure (Cambridge University Press 2010).

Guilfoyle D, International Criminal Law (Oxford University Press 2016).

Politi M, The Rome Statute of the International Criminal Court: a challenge to impunity (Routledge 2017).

Shukri MA, ‘Will Aggressors Ever be Tried before the ICC’, in Mauro Politi, The International Criminal Court and the Crime of Aggression (Routledge 2017).

Journals

Clark RS, ‘Negotiating provisions defining the crime of aggression, its elements and the conditions for ICC exercise of jurisdiction over it’ (2009) 20(4) European Journal of International Law 1103.

Ferencz BB, ‘Ending Impunity for the Crime of Aggression’ (2009) 41 Case Western Reserve Journal of International Law 281.

Heller KJ, ‘Retreat from Nuremberg: the leadership requirement in the crime of aggression’ (2007) 18(3) European Journal of International Law 477.

Jennings RY, ‘The Caroline and McLeod Cases’ (1938) 32 American Journal of International Law 82.

Jia BB, ‘The crime of aggression as custom and the mechanisms for determining acts of aggression’ (2015) 109(3) American Journal of International Law 569.

Kirsch P and Holmes JT, ‘The Rome conference on an International Criminal Court: the negotiating process’ (1999) 93(1) American Journal of International Law 2.

Leclerc-Gagne E and Byers M, ‘A Question of Intent: The Crime of Aggression and Unilateral Humanitarian Intervention’ (2009) 41 Case Western Reserve Journal of International Law 379.

Nußberger, ‘The War between Russia and Georgia – Consequences and Unresolved Questions’ (2009) 1 Göttingen J Int’l L 341

O'Connell ME and Miyazmatov M, ‘What is Aggression-Comparing the Jus de Bellum and the ICC Statute’ (2012) 10 J. Int'l Crim. Just. 189.

Paulus A, ‘Second thoughts on the crime of aggression’ (2009) 20(4) European journal of international law 1117.

Scharf MP, ‘How the War Against ISIS Changed International Law’ (2016) 48 Case W. Res. J. Int'l L. 16.

Stahn C, ‘Complementarity, amnesties, and alternative forms of justice: some interpretative guidelines for the International Criminal Court’ (2005) 3(3) Journal of International Criminal Justice 695.

Weisbord N, ‘The mens rea of the Crime of Aggression’ (2013) 12 Wash. U. Global Stud. L. Rev. 487.

Websites

Koh HH, ‘Statement Regarding Crime of Aggression at the Resumed Eighth Session of the Assembly of States Parties of the International Criminal Court’ (23rd March 2010) accessed

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