Thank you for that introduction and to my distinguished fellow panelists. And thank you to the American Society of International Law for the opportunity to speak here today on this important panel.

As Michael has noted, governments have spent considerable time hashing through the many legal questions raised by the amendments on the crime of aggression that were ultimately adopted at the ICC’s 2010 Review Conference in Kampala. My purpose today is less to further debate those questions, but rather to offer a perspective on the policy implications of these amendments. We in the U.S. Government are concerned about the potential of these amendments to have lasting negative effects, and we see it as vital that the states involved in this process work together to avoid harming our common ability to prevent atrocities, resolve conflicts, and pursue justice for the worst global crimes.

Let me start by underscoring that – notwithstanding the quite serious concerns I will express here today – I am not questioning the motives of our many friends and allies who have been supportive of the Kampala amendments. Like them, we fully agree that aggression is inimical to a rules-based international order, and to the cause of peace and security that we seek to advance through our efforts around the world every day. Russia’s attempt to annex Crimea, to choose just one recent example, serves as a reminder that the international community will continue to face an ongoing imperative to oppose aggression as a significant policy challenge.

The question, however, is whether the Rome Statute amendments can be an effective and appropriate addition to the international community’s tool-box. And here, as I will explain in greater detail, I think the risks of the current amendments outweigh the benefits. We will continue to work to persuade our partners of this, but we also know that for some, opposing these amendments in total may not be an option. For this reason, we propose that other states think seriously about how can they mitigate some of the greatest risks that we see as inherent in the current amendments.

Taking a step back, we recognize that this is a challenging issue, that many years of preparatory work informed the decisions made in Kampala, and that the Review Conference took steps aimed at addressing at least some of the concerns that were raised there. We welcomed, for example, the decision of the parties to exclude from the Court’s jurisdiction over aggression the nationals of countries that are not party to the Rome Statute. And we welcomed the decision to defer until 2017 at the earliest any decision to activate that jurisdiction, which have provided breathing space and time in which important and still outstanding issues presented by the amendments could be addressed. At this point, however, we are well into the fifth year of this seven-year period, and it is becoming ever more pressing that the international community make productive use of this reflection time.

Many of our concerns – and many of the means of mitigating them – are linked to the uncertainty that still surrounds crucial aspects of the amendments and how they may be interpreted and applied. The definition of the crime itself, as adopted in Kampala, was ostensibly based on an earlier UN resolution that gave guidance to the Security Council on identifying acts of aggression. But the definition that the parties adopted stripped away the critical requirement that the assessment of a use of force “must be considered in light of all the circumstances of each particular case,” and it shifted the role of applying this guidance and making these judgments – which inevitably involve political judgments – from the Security Council to a judicial body meant to remain above politics. This makes the need for clarity all the greater.

Some of the formal understandings that were adopted in Kampala helped at the margins to clarify which acts will and will not be covered – but there remains little clarity or consensus about the meaning of core elements of the definitions. Our concerns about uncertainty have been exacerbated by the efforts of some supporters of the amendments to promote an interpretation – which we believe flies clearly in the face of the plain language of the Rome Statute – contending that the Court’s aggression jurisdiction would extend even to the nationals of states parties that do not ratify the amendments.

Now, why do these open questions matter so much for those who work on peace and security or to promote international justice? Some degree of uncertainty may be inevitable when a text of this complexity is negotiated. But the questions I have referenced are at the heart of the fundamental policy choices that the states supporting the amendments need to make. They therefore should address these uncertainties squarely now. The alternative – simply trusting or hoping that the Court itself will eventually “figure it out” when live cases involving actual defendants come before it, and only after a period of chilling uncertainty – this alternative seems risky and inappropriate given the magnitude of the associated issues. The activation of the Court’s aggression jurisdiction would be a highly consequential, even unprecedented, intervention into the international security architecture, and if the ICC’s states parties proceed, they have an obligation to resolve outstanding questions.

Let me detail three specific concerns about the activation of the Court’s aggression jurisdiction.

First, we are concerned that activation could chill the willingness of states to cooperate in certain military action where the legal basis for that action might be contested, including action aimed at stopping the very kinds of outrages, including mass atrocities, that prompted the Court’s creation. President Obama has emphasized the importance of collective action by a broad range of allies and partners when we deal with these threats to humanity. But many of our allies and partners are parties to the Rome Statute, and it is easy to imagine the complications and the chilling effect that could arise in any number of situations involving ethnic cleansing or other atrocities where the imperative for action is overwhelming. Imagine – in such a situation after the Court’s aggression jurisdiction has been activated – the Prime Minister of a Rome Statute party being told by her Legal Advisors that they could not guarantee or reliably advise that the Court would not regard a decision to join or support a coalition as aggression. Given current uncertainties, the legal advisors might advise that the ICC Prosecutor could well undertake an investigation of the matter and even pursue criminal proceedings and an arrest warrant. The international community has grappled for decades with the challenges of mobilizing the will to prevent humanitarian catastrophes. We fear that one of the effects of activating the ICC’s aggression jurisdiction will be to create new potential obstacles to military action when it is urgently needed to save innocent lives.

Second, we are concerned that activation of the amendments may reduce the ability of the international community to manage and resolve conflicts. While the international community has strived for consensus around the principle that atrocities cannot legitimately be the subject of an amnesty, it is not obvious that the same approach is appropriate for the crime of aggression, which is of a fundamentally different character. Imagine two states in conflict, each having accused the other of starting the war but both prepared to make peace. The United Nations has said that it will not endorse provisions in peace agreements that include amnesties for mass atrocities. But should the international community similarly insist that parties to a conflict not “take off the table” prosecution of the leaders of one side or another for resorting to force in a “manner inconsistent with the Charter of the United Nations”? Particularly with so little certainty about how the Court will interpret the substance of the amendments, is the international community ready to insist that these are crimes that must be prosecuted in every instance at any cost? That these are crimes that cannot go unpunished?

A third concern is that activation of the aggression jurisdiction will harm the Court’s ability to carry out its core mission – deterring and punishing genocide, crimes against humanity, and war crimes. Let me be clear: while the U.S. Government has a complex relationship with the ICC, we have worked to promote the Court’s success in a wide range of contexts and have expressed our support for each of the situations in which ICC investigations and prosecutions are underway. But the ICC is still working to establish and sustain a record of effectiveness in the basic functions by which its success will be measured, such as apprehending defendants, protecting its witnesses, and prosecuting cases already underway. How will a Court that is already struggling to fulfill its core mandate respond to the additional burden of the kind of decisions it would have to make under the Kampala amendments? The assessments involved in prosecuting aggression will inevitably be deeply political: which actor bears responsibility for a conflict; who has acted legitimately in self-defense? The Court would find itself in a role better suited for political actors, particularly if it seeks to prosecute a crime that lacks both a clear definition and the extensive jurisprudence that has developed around many atrocity crimes.

While the United States is not a party to the Rome Statute and its nationals would be explicitly excluded from the ICC’s aggression jurisdiction, we nonetheless have a deep interest in the outcome of the states parties’ deliberations on this issue – as do all who share the responsibilities and bear the risks of combating atrocities and underwriting global security. This brings me back to what I proposed at the beginning, which is that, for states that entertain the possibility of supporting these amendments to the Statute, we think it is crucial to focus on whether the risks that have been identified here can be sufficiently managed before taking the very consequential decision of whether to activate this new basis of jurisdiction.

In this connection, let me offer at least some preliminary thoughts on some of the risk mitigation measures that could be considered:

• Governments and parliaments of states parties could formally state their views on the questions raised here. They can clarify the scope of which acts are covered and confirm that the amendments do not apply to states parties that do not ratify the amendments. They could do this, for example, in statements at upcoming sessions of the ICC’s Assembly of States Parties, or in written instruments communicating their decision whether or not to ratify.

• Perhaps most critically, if there were eventually a decision by the Assembly of States Parties to activate the amendments, states could insist that that decision contain clear guidance on these issues.

• States parties could clarify how the “opt-out” provisions contained in the amendments might be used to help address the concerns raised here and serve as a guardrail or check on an overly broad application of the amendments.

• States parties could also consider other steps, including the possibility of adopting further understandings to ensure these amendments do not work at cross-purposes to the critical goal of preventing atrocity crimes.

To be sure, the activation of the Court’s jurisdiction over aggression is not a step that the United States has sought. Still, I trust we can continue this international dialogue in a spirit of good faith and with the urgency it deserves. We look forward to working with other countries and members of civil society to help ensure full consideration of the risks I have described and mitigation measures such as those that have been sketched out.

Thank you.