Prosecuting the Crime of Aggression as a Complement: A Framework to Promote the International Criminal Court's Legitimacy in Head-of-State Prosecutions

55 Pages Posted: 19 Oct 2018 Last revised: 10 Jul 2019

See all articles by Cara Cunningham Warren

Cara Cunningham Warren

University of Detroit Mercy School of Law

Date Written: August 31, 2018


There have been wide-ranging responses to the Assembly of States Parties’ decision to activate the Court’s power to prosecute the crime of aggression, but they share one commonality: Each in its own way would misguide the Court in terms of its next steps.

On one hand, there is cause for celebration. For the first time since Nuremberg and Tokyo, an international tribunal has jurisdiction over the "supreme international crime [that] contains within itself the accumulated evil of the whole." On the other hand, the Court's aggression jurisdiction is limited, thus some characterize activation as a symbolic gesture or urge the Court to pursue Security Council referrals to augment the Court's jurisdictional limitations.

Although understandable, these reactions should not guide the Court's course of action. We should not be lulled into a post-celebration ease. Nor should we think that a symbolic event does not require a concrete response. Nor should we reverse the Court's step toward maturation by immediately ceding power to another international body.

Activation, in fact, requires the Court to take immediate action to prepare for the Head-of-State (HOS) prosecutions to come. The Court should continue to develop its legitimacy and a normative framework to maintain it. In particular, prosecuting the leadership crime of aggression opens Pandora's Box regarding one of the Court's most difficult chapters: Head-of-State or HOS prosecutions.

This paper evaluates activation consequences and next steps through the lens of legitimacy theories — namely consent, efficacy, and procedural fairness. Section II identifies several legitimacy pitfalls that will undermine HOS prosecutions if left unresolved: questions of consent related to the relatively small number of participating states; questions of consent related to undeveloped complementarity rules in the HOS aggression context; questions of efficacy regarding the Court’s inability to pursue successfully a case against a sitting Head of State; and questions regarding procedural fairness.

To address these legitimacy issues, Section III suggests that the Office of the Prosecutor adopt a special Prosecutorial Framework for HOS aggression situations. It would expand the existing preliminary examination analysis to address complementarity questions unique to HOS aggression prosecutions. It also would expand the interests of justice considerations to include an evaluation of the Court's capacity to investigate and prosecute — with an aim of building the Court's legitimacy. The framework also calls for the use of a constructivist methodology that will incentivize participation. Constructivist norm building that produces successful HOS prosecutions is a critical need, and the new Prosecutorial Framework introduced in this paper would achieve this end.

Keywords: International Criminal Court, aggression, Head of State, immunity, complementarity

Suggested Citation

Cunningham Warren, Cara, Prosecuting the Crime of Aggression as a Complement: A Framework to Promote the International Criminal Court's Legitimacy in Head-of-State Prosecutions (August 31, 2018). George Washington International Law Review, Vol. 51, 2019, Available at SSRN:

Cara Cunningham Warren (Contact Author)

University of Detroit Mercy School of Law ( email )

651 E. Jefferson
Detroit, MI 48226
United States

Do you have negative results from your research you’d like to share?

Paper statistics

Abstract Views
PlumX Metrics