Skip to content

Coming Together to End Aggression

by Professor Mary Ellen O'Connell

Prof. O’Connell argues that activating the crime of aggression completes the International Criminal Court’s project, and the U.S. should support this development, not hinder it.

In a surprising development, two former State Department Legal Advisers from very different administrations are again taking a common stand on a high-profile human rights issue. John Bellinger from the Bush administration and Harold Koh from the Obama administration are both criticizing amendments to the International Criminal Court’s (ICC) Rome Statute that will add the crime of aggression to the court’s jurisdiction.[1] The crime of aggression, as will be discussed further below, involves the use of armed force in violation of the United Nations Charter. In 2014, the former legal advisers joined force to advocate for a change in U.S. policy to recognize more broadly that human rights obligations apply extraterritorially.[2]

These two positions, on the aggression amendments and extraterritoriality, are in fact deeply incompatible, and the international human rights community has reacted very differently to them. Many applauded the position on extraterritoriality but are denouncing the opposition to the aggression amendments. As a practical matter, too, the positions are different. The United States acts abroad in a myriad of ways, so changing the extraterritoriality policy will presumably have a major impact on United States overseas activities. By contrast, even if the aggression amendments come into force, the chance of an American ever being prosecuted is extremely remote. It bears asking why these prominent lawyers would spend their time warning of the negative consequences of something so unlikely to occur.

From the perspective of Bellinger and Koh, however, opposition to the aggression amendments and support of extraterritoriality makes sense. Both issues implicate America’s reputation in the world as a human rights beacon. To be a leader means having a strong reputation for respecting and promoting human rights. On extraterritoriality, Bellinger and Koh call for U.S. compliance in order to be on the right side of the issue. On aggression, however, the two are content to obscure U.S. non-compliance. A consistent approach to both issues, however, will serve the United States and the world far better.

With respect to the issue of extraterritoriality, the U.S. is regularly monitored, criticized, and called to account for human rights violations abroad. Trying to defend against accusations by arguing that a particular treaty does not apply abroad was simply falling on deaf ears. Since holding fast to the old policy was doing the U.S. no favors, the two former legal advisers saw the wisdom in changing the policy.

By the same logic, if it is highly unlikely that a U.S. official or national would ever be prosecuted – as Bellinger and Koh firmly believe – , then why oppose the aggression amendments that are popular with many human rights advocates?[3] In a recent post on Lawfare, Bellinger gave credit to Koh for “a critical diplomatic success by persuading Rome Statute parties to agree that the crime of aggression will apply only to nationals or on the territory of Rome Statute parties.” He could have added that Koh also succeeded in assuring that the amendments encompass only a highly restrictive criminal provision, one that diverges significantly from the actual prohibition on aggression binding on states.[4] The amendments would make it difficult to even prosecute Vladimir Putin for Russia’s use of force in Ukraine because the agreed terms were designed to exclude cases of humanitarian intervention.

Not only is the substance of the definition of the ICC crime of aggression restrictive, the delegates at the Rome Statute 2010 review conference in Kampala, Uganda agreed to tough procedural hurdles to slow the “activation” of the ICC’s jurisdiction. After 30 states ratify the amendments, nothing can be done prior to January 1, 2017. At that point a minimum notice period begins after which, if consensus on the amendments is not reached, a two-thirds vote of States Parties is required. As Professor David Bosco points out, African ICC State Parties will be reluctant to activate making it difficult to reach consensus or the two-thirds number.[5] The two-thirds requirement has also created uncertainty around the operation of the amendments and whether they will apply only to the ratifying states or all ICC members, including those who vote against ratification.[6]

Given these hurdles, the timing of Bellinger and Koh’s comments is revealing. The 30th ratification will likely occur during 2016. That fact alone is creating new interest around the crime of aggression, and that new interest is coinciding with an increasingly critical global stance against war—a stance completely understandable in light of the terrible consequences of armed conflict. In 2014, 38 million people were displaced by war, the most in history. It is estimated that 180,000 died and many times that number suffered physical and psychological injuries. Destruction of the built and natural environment was vast.

The U.S.-led invasion of Iraq in 2003 is linked, along with persistent drone attacks, to the conditions that helped give rise to the so-called Islamic State and escalation of the civil wars in Iraq and Syria. Russia’s claimed right to intervene on behalf of an oppressed minority in Ukraine takes the world back to similar claims by NATO respecting Kosovo in 1999. Whether or not American or Russian leaders are ever prosecuted for these interventions, attention to the amendments keeps these uses of force in violation of the Charter alive in the public mind.

Taking the position that the U.S. is a human rights leader in contrast to other states is difficult in the light of such a record. Criticizing the amendments, therefore, makes sense if downplaying the past is the aim. Bellinger and Koh’s approval of senior State Department official Sarah Sewall’s criticisms of the aggression amendments support this hypothesis. Sewall worries, for example, that the ICC prosecutor will be distracted from her “core” job of prosecuting genocide, war crimes, and crimes against humanity by adding the crime of aggression. Sewall also believes that prosecuting aggression may hinder peace negotiations, and she says prosecuting aggression may prevent the use of force for humanitarian intervention as in Kosovo. She suggests that if national leaders fear being prosecuted for aggression they will not join coalitions to intervene.[7]

This last example seems to be the core issue. ICC indictments for crimes other than aggression have already disrupted a number of important peace negotiations, but Sewall has no problem with continuing to prosecute those crimes despite the negative consequences for peace.[8] She says in fact that prosecuting these other crimes are the “core” task of the ICC prosecutor in distinction to aggression. Yet, aggression has been as much or more of a “core” international crime since the development of international criminal prosecutions.

Sewall’s arguments—and Bellinger’s and Koh’s support of them—attempt to minimize the central place of the law against war in the international legal system. Yet, from the development of modern international law at the end of the Thirty Years War in Europe in 1648, the very purpose of international law has been to restrict military intervention and foster peaceful settlement of disputes. Substantial evidence confirms this, including the attempt to prosecute the German Kaiser after World War I for “a supreme offense against international morality and the sanctity of treaties”.[9] The 1919 Covenant of the League of Nations expressly committed states to protect other states from “external aggression.”[10] At the Nuremberg Tribunal after World War II, “aggression” was declared to constitute the “supreme international crime.”[11] The United Nations Charter adopted in 1945 begins by explaining the UN exists “to save succeeding generations from the scourge of war.” The Charter’s most important provision is the general prohibition on resort to force in Article 2(4). The Charter includes only two express exceptions to the prohibition, one for self-defense if an armed attack occurs and one for Security Council authorized actions.

In 1974, U.N. members agreed in Resolution 3314 that any first use of force in violation of the United Nations Charter is prima facie evidence of an act of aggression. The Resolution also provides an illustrative list of examples that reach the Russian failure to remove its troops from Crimea as well as assistance to rebels in Eastern Ukraine, NATO’s use of force against Serbia in 1999 during the Kosovo crisis, and the coalition invasion of Iraq in 2003.

After the Iraq invasion, the U.N. Secretary General undertook a comprehensive review of the United Nations Charter provisions on the use of force. At the end of the review in 2005, all U.N. members came together for a world summit in New York. They agreed the Charter needed no changes and committed to abide “strictly” by the Charter’s terms respecting the use of force. [12] That commitment was made in the full understanding that the International Court of Justice has referred to the prohibition of aggression as a jus cogens norm admitting no derogation.[13]

Sewall and Koh supported the Kosovo intervention, which lacked Security Council authorization and had nothing to do with U.S. self-defense. They nevertheless seem to believe that the intervention and others like it for humanitarian purposes are lawful. The Koh-led U.S. delegation to the 2010 Kampala review conference’s “single most sensitive” proposal was to exclude humanitarian intervention from the scope of the aggression amendments.[14] The U.S. is not a party to the ICC’s Rome Statute and is unlikely to become one any time soon, but the American delegation nevertheless felt it important to go to Kampala to try to prevent agreement on including the crime of aggression. It was not enough to raise barriers to prosecuting Americans. Now Koh, Sewall, and Bellinger do not want the amendments to enter into force.

In my view, including the crime of aggression in the Rome Statute was essential for the whole project of the ICC to make sense. The Nuremberg and Tokyo Trials were the impetus for the ICC. Those trials held that the crime of aggression was the most significant wrongful action committed by the defendants. The waging of unlawful war, then as now, created the conditions in which other serious crimes could occur, including crimes against humanity, war crimes, and genocide. To be limited to prosecuting lesser crimes such as destroying antiquities while lacking the capacity to charge the leader responsible for starting the armed conflict in which those lesser crimes occurred lacks rational coherence.

The United Nations Charter prohibition on the use of force has been under pressure for decades by a variety of governments seeking exceptions to the prohibition on force. As described above, the international community has consistently supported and strengthened the law against force. Supporting the aggression amendments is another opportunity to bolster the law against war.

If it is in the interest of the U.S to re-gain its leadership on human rights, the best way to accomplish this is to advocate U.S. compliance with the law that protects human rights more than any other – the prohibition on aggression. Preventing the aggression amendments from entering into force will not foster human rights. Ending war will. Even if no one is actually prosecuted for aggression, having a viable crime on the books will support the norm.

The world needs leadership on human rights. It especially needs a champion for the human right to peace. The nation that took the lead in drafting the Nuremberg Charter and the United Nations Charter is a natural for that role. Bellinger and Koh are just the people to help make it happen. Rather than attempting to obscure the United States’ unlawful uses of force by opposing the ICC aggression amendments, Bellinger and Koh could accomplish great good by joining forces in the cause of peace.

[1] Harold Hongju Koh and Todd F. Buchwald, The Crime of Aggression: The United States Perspective

109 Am. J. Int’l L. 257 (2015) and John Bellinger, USG Concerns with the ICC Aggression Amendments, Jan. 5, 2016, Lawfare,

[2] See John Bellinger, III and Harold Koh, Bringing International Human Rights Back Home?, Nov. 11, 2014, Woodrow Wilson School of Public and International Affairs, Princeton University,

[3] Global Campaign for Ratification and Implementation of the Kampala Amendments on the Crime of Aggression,

[4] Mary Ellen O’Connell and Mirakmal Niyazmatov, What is Aggression?: Comparing the Jus ad Bellum and the ICC Statute, 10 J. Int’l Crim. J. 189 (2012), available at

[5] See David Bosco, Who’s Afraid of Aggression Prosecutions?, Lawfare, Jan. 8, 2015.

[6] See Bellinger above.

[7] These would be coalitions lacking Security Council authorization as in Kosovo 1999. If the Security Council authorizes an intervention, there would be a lawful basis for the initial resort to force. Other conditions apply, however, including demonstrations that the use of force is a last resort and is likely to accomplish the military objective.

[8] Concern about the impact of ICC indictments on peace talks has existed since the Rome conference to draft the ICC Statute in 1998. The concern has been warranted as ICC indictments are already associated with failed peace talks in a number of armed conflicts, including Sudan, Uganda, Syria, and Colombia. Also, following ICC indictments the intensity of fighting increased in the Libyan civil war that began in 2011. See Rodrigo Uprimny and Nelson Camilo Sánchez, The ICC and Negotiated Peace: Reflections from Colombia, openDemocracy, Feb. 11, 2015ánchez/icc-and-negotiated-peace-reflections-from-col and Mary Ellen O’Connell, International Dispute Resolution, Cases and Materials 255 (2d ed., 2012).

[9] The Treaty of Versailles, June 28, 1919, relevant provisions reprinted in O’Connell, International Law and the Use of Force, ibid., at 142.

[10] Covenant of the League of Nations, reprinted in O’Connell, International Law and the Use of Force, ibid., at 139-141.

[11] International Military Tribunal (Nuremberg), Judgment and Sentences, 1 October 1946, reprinted in 41 Am. J. Int’l L. 186 (1947).

[12] 2005 World Summit Outcome, UN GAOR, 60th Sess., at 22-23, U.N. Doc. A/60/L.1 (Sept. 15, 2005).

[13] The International Court of Justice noted that both the United States and Nicaragua had referred to the United Nations Charter prohibition on the use of force in Article 2(4) as a jus cogens norm. Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America), International Court of Justice, 27 June 1986, ICJ Reports (1986) 14, at 100-101 (para. 190).

[14] Clauss Kress and Leonie von Holtzendorff, The Kampala Compromise on the Crime of Aggression, 8 J. of J. Int’l Crim. Justice 1179, 1205 (2010).

If it is in the interest of the U.S to re-gain its leadership on human rights, the best way to accomplish this is to advocate U.S. compliance with the law that protects human rights more than any other – the prohibition on aggression. Preventing the aggression amendments from entering into force will not foster human rights. Ending war will.

— Prof. Mary Ellen O'Connell

Professor Mary Ellen O'Connell

Mary Ellen O’Connell is the Robert and Marion Short Professor of Law and Research Professor of International Dispute Resolution—Kroc Institute for International Peace Studies, University of Notre Dame, USA. Her recent publications include 21st Century Arms Control Challenges: Drones, Cyber Weapons, Killer Robots, and WMDs, 13 Wash. U. Global Stud. L. Rev. 515 (2015); Chapter One: Historical Basis and Legal Development, in The Handbook of International Humanitarian Law (D. Fleck ed. 3rd ed. Oxford, 2013), and What is War? An Investigation in the Wake of 9/11 (editor, Martinus Nijhof/Brill 2012.) She chaired the International Law Association’s Committee on the Use of Force from 2005 to 2010 and was a vice president of the American Society of International Law (2010-2012.) Professor O’Connell is a member of the German and European Societies of International Law and the International Institute of Humanitarian Law—San Remo. She was a professor at the George C. Marshall European Center for Security Studies, Garmisch-Partenkirchen (1995-1998).