Crime of Aggression : Fusion of Jus Ad Bellum and Jus In Bello?

Written by Garima Tiwari

The Principality of Liechtenstein became the first country to ratify the Kampala amendments to the Rome Statute of the International Criminal Court (“ICC”) on the crime of aggression. Only one other country, Samoa has ratified the amendments on 25th September, 2012.[i] However, a total of 30 ratifications by States Parties are required as a condition for ICC to exercise jurisdiction over this crime in the future, no earlier than 1 January 2017.[ii] While we await the ratifications, an issue which was raised and would be raised, needs a look – what would be the impact of bringing together –jus in bello and jus ad bellum within the jurisdiction of same court for the crime of aggression?

At the core of the jus in bello is the principle that, regardless of the legality of the armed conflict (as determined by the jus ad bellum), all combatants have the same rights and duties in warfare. [iii] The most concrete distinction between the jus ad bellum and the jus in bello can be found in the Statutes of the Nuremberg and Tokyo Tribunals.[iv] For instance, one decides whether the use of armed force constitutes aggression or self-defence in accordance with jus ad bellum.[v] Extending the reach of international criminal law may generate indirect negative effects from the interaction of the ICC’s potential to prosecute the crime of aggression and the long-standing jus in bello, that body of rules governing how war is waged rather than why war is waged, which is the purview of the jus ad bellum.[vi]

It is contended that while genocide, crimes against humanity and war crimes are jus in bello crimes, dealing with comparatively straightforward factual questions (eg. the occurrence of a massacre, issuance of orders).  Aggression concerns jus ad bellum, and can entail subtle public international law questions, such as self-defence, territorial claims, self-determination or responsibility to protect. [vii] A violation of jus ad bellum is mainly thought to be a matter incurring state responsibility. When it comes to individual criminal responsibility for a violation of jus ad bellum, the definition of aggression has revealed it is a leadership crime, committed by a person “being in a position effectively to exercise control over or to direct the political or military action of a State”.Another way of reading this is that crime of aggression, is based on acts committed by the state, and fundamentally differs from the other three core crimes which are jus in bello crimes directed against particular individuals.[viii] The notion that an individual should be held liable for his or her contribution[ix]to the criminal conduct certainly lies at the heart of the general principles of individual criminal responsibility as provided for in Article 25 of the Rome Statute. [x]

It is no accident that the intellectual ‘father’ of the crime of aggression and the Nuremberg trials, William Chandler, wanted to do away with this distinction altogether,[xi]  thus  demonstrating that the crime of aggression is not easy to combine with the prosecution of violations of jus in bello. There has been rarely any argument which represents a fusion of the jus ad bellum and the jus in bello in aggression as an international crime with individual liability attached to it.[xii]

The legality of the decision to use force necessitates an inquiry into state action, and often involves foreign policy best left outside the court. Decisions regarding jus ad bellum, regardless of whether the defendant is a state or an individual, are laced with political issues and should remain with the U.N. Should the Council after determining the former issue then refer violations of jus in bello to the ICC, that would be appropriate.  Only in this regard is the complementary relationship between jus ad bellum and jus in bello kept intact. [xiii]

The impelling concern that was and still remains is that if the leadership of one party has already been singled out by ICC as the culprit in an armed conflict, what incentive does it have for upholding the jus in bello? [xiv] We need to wait and see how ICC handles the pressure, avoid getting politicized and balance the fusion while keeping itself aware of its purpose.

[ii] Press Release: Liechtenstein first country to ratify the Kampala amendments  on the crime of aggression,

[iii] Gerhard Kemp,Individual Criminal Liability for the International Crime of Aggression,  Supranational Criminal Law Volume 7 (2010)

[iv] Yoram Dinstein,The distinctions between war crimes and crimes against peace,in Yoram Dinstein and Mala Tabory War crimes in International Law (1996) Kluwer Law International, The Hague, 1-18.

[v]  Machteld Boo, Genocide, Crimes Against Humanity, War Crimes: Nullum Crimen Sine Lege and the Subject Matter Jurisdiction of the International Criminal Court, School of Human Rights Research , 6

[vi] Beth Van Schaack,The Grass That Gets Trampled When Elephants Fight: Will the Codification of the Crime of Aggression Protect Women?(2010) ExpressO Available at:

[vii] Darryl Robinson, ICC Review Conference Opens in Kampala; Features Intriguing Hybrid Character, May 31,2010 available at

[viii] Anderson, The Rise of International Criminal Law: Intended and Unintended Consequences’, 20 EJIL (2009) 331, at 354.

[ix] David Rodin, War & Self-Defense (2002) Clarendon Press, Oxford, 167at  173

[x] Steven Nicholas Haskos, An Argument for the Deletion of the Crime of Aggression from the Rome Statute

of the International Criminal Court, 23 Pace Int’l L. Rev. 249 (2011)

Available at:

[xi] See the letter reprinted in Bush, ‘The “Supreme Crime” and its Origins: The Lost Legislative History of

the Crime of Aggressive War’, 102 Columbia L Rev (2002) 2324, at 2402.

[xii] Christopher Greenwood ,Scope of Application of Humanitarian Law in Dieter Fleck (ed) The Handbook of Humanitarian Law in Armed Conflicts (1995) Oxford University Press, Oxford, 39 – 63

[xiii] James Nicholas Boeving, Aggression, International Law, and the ICC: An Argument for the Withdrawal of Aggression from the Rome Statute, 43 COLUM. J. TRANSNAT‟L  L. 557, 582-3 (2005).

[xiv] Andreas Paulus, Second Thoughts on the Crime of Aggression, Eur J Int Law (2009) 20 (4),1117-1128.