The International Criminal Court and the Crime of Aggression

Columbia Law School's Human Rights Institute Co-sponsors a Briefing for UN Legal Advisers on Extending the Jurisdiction of the International Criminal Court
New York, May 4, 2016—The prospect of the International Criminal Court (ICC) prosecuting powerful political and military leaders for the crime of aggression was considered at a breakfast briefing of legal advisers from more than a dozen state missions to the United Nations who gathered at German House in New York City.
Sarah Cleveland, co-director of the Human Rights Institute and the Louis Henkin Professor of Human and Constitutional Rights at Columbia Law School, moderated the discussion on the prospect of the International Criminal Court prosecuting political and military leaders for the crime of aggression.
The February event was sponsored by the Human Rights Institute at Columbia Law School, the German Center for Research and Innovation, and the University of Cologne, and was moderated by Sarah Cleveland, co-director of the Human Rights Institute and the Louis Henkin Professor of Human and Constitutional Rights at Columbia Law School.
The briefing attracted legal advisers from numerous state missions to the UN, including the nations of Australia, Botswana, Brazil, China, Denmark, Estonia, Hungary, Japan, Korea, Mexico, The Netherlands, Norway, Romania, Switzerland, the United Kingdom, Uruguay, and the United States, as well as representatives from non-governmental organizations and students from Columbia Law School.
In addition to Cleveland, the presenters were:

Harold Hongju Koh, the Sterling Professor of International Law and former dean of Yale Law School, former legal adviser to the U.S. State Department, and onetime U.S. Assistant Secretary of State for Democracy, Human Rights and Labor; and

Claus Kress, a visiting scholar in residence at Columbia Law School, as well as the director of the Institute of International Peace and Security Law and professor of criminal and public international law at the University of Cologne. Professor Kress is a world expert on international criminal law.

The world’s first permanent criminal court, the ICC takes its authority from a 1998 treaty among more than 120 countries. It already has a mandate to prosecute individuals for crimes against humanity, war crimes, and genocide committed after July 1, 2002, but not yet for aggression, which has been recognized as a supreme international crime since the 1946 Nuremberg trials. In 2010, 26 state parties to the ICC reached consensus on the definition of a crime of aggression—including the invasion, occupation, or annexation of states by the use of force—but they postponed the decision to activate the ICC’s jurisdiction until 2017. 
In 2010, said Cleveland, the 2017 deadline “seemed a very long way away, like the elephant on the horizon seems very small. Now the elephant is looking much larger, as 2017 is just around the corner.” In introducing Koh and Kress, Cleveland said, “There are no two people better equipped to discuss the topic.”
Although the United States actively participated in the negotiation of the 1998 Rome Statute that established the ICC, the United States has not ratified the treaty and has never participated in the court. President Clinton signed the statute in 2000, and Koh both led America’s reengagement with the ICC during the early years of the Obama administration, and headed the U.S. delegation to the 2010 conference that considered the crime of aggression. Koh expressed his personal support for the court’s success “as an effective mechanism for international criminal justice and human rights,” but indicated concern that the world community would “sleepwalk” to adopting the crime of aggression “at a scope it cannot manage,” creating an “extremely dangerous and I should say threatening” development for the court’s future.
Koh called for another review conference in 2017, where the issue could be debated and addressed collectively. He posed a question to the legal advisers present: “If you have not ratified the crime of aggression, but 30 countries do, one year later are you bound?” “We have a problem,” Koh said. “People do not know whether they will be bound once 30 states ratify, and there’s a real possibility they will be silently bound [under their existing obligations under the Rome Statute]. This is not something that can be ignored. . . . There is still time to work on it, but not time to ignore it.”
He was particularly concerned the crime of aggression was framed too broadly and could be used to stop humanitarian interventions. “For those countries who are still in doubt, my personal suggestion would be that you adopt a specific, partial opt-out declaration at the time of ratification with regard to issues of intervention to prevent crimes of atrocity,” Koh said. “How can it be inappropriate to exclude from the crime of aggression the use of force to prevent the crimes that the Rome Statute is trying to criminalize?”
Kress, on the other hand, noted that the points of uncertainty that remain with respect to the crime of aggression are quite narrow. He underscored that to constitute a crime of aggression the illegality of a use of force must be “manifest”, and pointed to the lengthy and complex negotiations that led to the 2010 agreement. He argued that there remained “very limited areas where disagreements exist and clarification may be welcome.” He stressed the “considerable—and many would say surprising—extent agreement and consensus has been reached.” Kress said it was clear that states that do not ratify the crime of aggression are not bound, and that states may clarify their obligations under the crime through declarations if they wish.  All state parties can choose to opt out. States that are not parties to the court “are not within the jurisdiction of the ICC, whatever happens,” even if another state party is involved.
“This is about military force, not economic coercion,” Kress said. “This is a leadership crime, the circle of perpetrators restricted to the upper echelons of the hierarchy.”
Among the legal advisers at the briefing was Stefan Barriga LL.M. ’02, minister and deputy representative of Liechtenstein’s Permanent Mission to the United Nations. Barriga was one of the primary drafters of the 2010 agreement on the crime of aggression and the ICC, and he had been a principal legal advisor to the negotiators since 2003. Barriga and Kress are the editors of The Travaux Préparatoires of the Crime of Aggression (Cambridge University Press).
Since 1998, Kress has represented Germany in state negotiations regarding the ICC. He was a visiting professor, and now visiting scholar in residence at Columbia Law School. The University of Cologne’s Institute of International Peace and Security Law, which Kress directs, includes on its advisory council Columbia Law School professors Cleveland and Matthew Waxman.