As shown by the trials of Slobodan Milosevic, Charles Taylor and Saddam Hussein, the large-scale and systematic commission of international crimes is usually planned and set in motion by senior political and military leaders. Nevertheless, the application of traditional forms of criminal liability leads to the conclusion that they are mere accessories to such crimes. This does not reflect their central role and often results in a punishment which is inappropriately low in view of the impact of their actions and omissions. For these reasons, international criminal law has placed special emphasis on the development of concepts, such as control of the crime and joint criminal enterprise (also known as the common purpose doctrine), which aim at reflecting better the central role played by senior political and military leaders in campaigns of large scale and systematic commission of international crimes. The Rome Statute of the International Criminal Court and the case law of the ICTY and the ICTR have, in recent years, played a unique role in the achievement of this goal.

Hector Olasolo is Professor of International Criminal Law and Procedure at Utrecht University and Chairman of the Iberoamerican Institute of the Hague for Peace, Human Rights and International Justice (IIH). LLM (Columbia University), PhD in Law (Salamanca University). Former Legal Officer in Chambers at the International Criminal Court (2004-2009). Former member of the Legal Advisory and Appeal Sections of the Office of the Prosecutor of the International Criminal Tribunal for the Former Yugoslavia (2002-2004). Former member of the Spanish Delegation to the International Criminal Court Preparatory Commission (1999-2002). The author has written the books entitled 'Corte Penal Internacional: ¿Dónde Investigar?' (Tirant lo Blanch, 2003), 'The Triggering Procedure of the International Criminal Court' (Brill Publishers, 2005), 'Ataques contra Personas y Bienes Civiles y Ataques Desproporcionados' (Tirant lo Blanch, 2006), 'Unlawful Attacks in Combat Situations' (Brill Publishers, 2007), 'Terrorismo Internacional y Conflicto Armado' (Tirant lo Blanch, 2008) and 'Ensayos sobre la Corte Penal Internacional' (Universidad Javeriana de Bogotá/Dyke, 2009). The views expressed herein are those of the author alone and do not necessarily reflect the views of the ICC, the ICTY, the United Nations or the Spanish Government.