To date, I have largely used this blog to host debates about other people’s scholarly work. In this instance, I wanted to host a discussion about an article I authored for a Festschrift in honor of Yale Professor Mirjan Damaška, which is entitled The Strangely Familiar History of the Unitary Theory of Perpetration. I thought to invite a range of judges, expert practitioners from international criminal law (“ICL”) institutions as well as scholars from countries that adopt the theory of blame attribution I advocate for to comment on the idea of abandoning “modes of liability” in ICL entirely. Somewhat strangely, the long debates about these questions in the field have mainly involved academics from dominant Western countries, but none of the world’s leading experts from jurisdictions that adopt the unitary theory of perpetration have had an opportunity to engage with the debate about whether we should have forms of participation in ICL or do without them as per their own national systems. Both the article and this symposium are an attempt to bring these perspectives to the fore without, of course, prejudging how these particular commentators will see the issues in question or respond to my treatment of them in the article.

I begin by introducing the discussion’s relevance for international law. To do so, I reiterate an argument I recently made about the significance of these issues for global governance. Modes of liability, or forms of attribution as they are probably better labelled, can be fairly arid, technical, technocratic concepts in the theory of criminal law that are not normally of great interest to international lawyers. But I want to depict them in a way that highlights their great regulatory potential on an international plane. If one thinks of all of the harms in the world on the one hand, then all of the actors operating globally on the other, modes are attribution are those devices that exist between these two sets, reaching into the ocean of actors to tie them to particular atrocities. One can therefore understand how these concepts can have huge implications for global regulation, even though they are cast in fairly technocratic language that can be quite alienating to international lawyers. Of late, there is seemingly a rising recognition of this fact for a variety of global issues, including counterterrorism, foreign assistance, and business.

Against this backdrop, let me introduce the unitary theory. A unitary theory of perpetration is one that does not espouse different legal standards for different forms of participating in crime. So, whereas modern international courts and tribunals employ different legal tests to differentiate aiding and abetting from joint criminal enterprise, superior responsibility and indirect co-perpetration, a unitary theory of perpetration condenses all of these standards into a singular unified standard that only requires a substantial causal contribution to the consummated offense together with the blameworthy moral choice announced in the crime with which the accused is charged. It is worth noting, however, that there are pure, functional and sentence-based variants of this unitary theory (for discussion, see here, pp. 8-10), which come with different contours. For present purposes, however, the key aspect of the unitary theory I want to emphasize is that the formal legal elements of blame attribution remain constant across the different relationships actors bear to atrocity.

Initially, international courts employed a unitary theory of perpetration in practice. Although the Nuremberg and Tokyo Charters explicitly enumerated different forms of attribution, the Nuremberg Tribunal itself often just considered whether an accused was “concerned in,” “connected with”, “inculpated in” or “implicated in” international crimes. As many leading commentators now accept, this approach entailed a functional unitary theory of perpetration, namely, a system of blame attribution that declined to disaggregate modes of participation into formal legal concepts like aiding and abetting, superior responsibility or JCE, instead holding the substantive elements of blame attribution constant across the various roles different actors might play. In the modern era, however, ICL absorbed dominant Western doctrine to supplant this history, first from the Anglo-American system then from Germany. Whatever one might say about these shifts as matters of customary international law, it is striking that neither set of practices was informed by the experience of states throughout the world that had abandoned modes of liability. This article and mini-symposium introduce that missing comparative experience.

Conceptually, this article is the sequel to a more conceptual piece I authored some years ago entitled The End of Modes of Liability for International Crimes. In that earlier article, I had argued that a conceptually coherent concept of complicity involves its disappearance into a more capacious single notion of perpetration, and that by the same analytical method, all modes of liability in international criminal law should suffer a similar fate. Having worked on these issues for many years as a practitioner before coming to the theory, my sense was that practically speaking too, the unitary theory of perpetration offered a way out of a difficult legal morass for practitioners. In my experience, standards for blame attribution are sometimes harsh, often unprincipled, in a constant state of flux and inconsistent with the expressive aspirations of the field across diverse cultures. At the very least, then, my hope was to invite robust scholarly defenses of the system in place. Moreover, I was particularly motivated to undermine the justification, which I heard a lot in practice, that the existing approach in ICL is defensible because several large Western states adopt it. To my mind, that argument is not sound.

Several prominent scholars, whose work I respect, have since offered helpful defenses of the differentiated system in response to my earlier argument (see Werle and Burghardt, Jackson, Steer). Although these excellent initial works certainly advance the debate, I am also convinced that the comparative experience I attempt to offer in The Strangely Familiar History of the Unitary Theory of Perpetration represents another important piece of the puzzle that has not figured in these debates before now. In the hope that others will pick up on aspects of these discussions to defend the differentiated approach or deepen thinking about the unitary theory, I am excited to host a range of prominent judges, one practitioner, and a host of leading scholars from each of the jurisdictions I discuss to participate in this mini-symposium (see list of commentators here). I am honored to have leading experts speaking for their own hitherto neglected legal traditions.