The Strongman’s Clause: Article 23(5), the Rules-Based International Order, and the Ukraine Tribunal’s Troubling Precedent

[Kate McInnes is a practicing lawyer based in Vancouver, Canada, and a student in the M.Sc. in International Human Rights Law program at the University of Oxford]

The creation of the Special Tribunal for the Crime of Aggression against Ukraine (STCAU), a court embedded within the Council for Europe framework, marks a historic effort in securing accountability for the most devastating conflict in Europe since World War II. It is a necessary step toward rectifying the fractured international order and delivering justice to victims of an illegal war of aggression, to which both states and individuals must be held accountable.

Embedded within its enabling statute, however, is a political compromise that threatens to undermine justice for Ukrainians and the credibility of international justice more broadly. The STCAU’s singular purpose, per Article 1, is “to investigate, prosecute and try persons who bear the greatest responsibility for the crime of aggression against Ukraine.” Yet Article 23(5) expressly prohibits the confirmation of an indictment if the accused is a sitting head of state, head of government, or foreign minister, and effectively suspends proceedings until that person either leaves office or waives immunity. Taken together, Article 1 and Article 23(5) create a contradiction: the STCAU Statute creates a tribunal with an exclusive focus on apex perpetrators, while simultaneously immunising many of those very individuals — namely, entrenched, authoritarian “strongmen” in Russia, Belarus, and potentially North Korea — from prosecution. 

Much has been said about the legality (or illegality) of the sort of immunity provided in Article 23(5), with the crux of the debate centred around whether the STCAU can properly be conceived of as an “international” court (see, for example, Coracini and Trahan, de Hoogh, Eboe-Osuji, Hamilton, Heller, McDougall, and Mullin and Stanton). These arguments rest on the assumption that the STCAU is a product of the traditional corpus of international law. 

This article does not seek to rehash these rich legal arguments, but to view the issue through an alternative lens. At its core, Article 23(5) reflects the swelling influence of a so-called “rules-based international order” (RBIO) over the traditional post-war international legal order. As John Dugard argues, RBIO functions less as a coherent legal system and more as an amorphous regime of pseudo-law which weakens efforts to sustain “a universal system of international law premised on the same fundamental rules, principles and values.” Under an RBIO, legal institutions discard or reinvent the established principles and legal rules generated over the past 80 years, in order to serve an (often) America-centric agenda. The result is not legal innovation, but legal erosion in the name of political compromise.

This article argues that Article 23(5) is a manifestation of RBIO’s troubling ascendancy. It also signals a deeper concern that political strategy, rather than precedent and principled legal reasoning, is shaping the architecture of international justice.

The STCAU’s Paradox: Targeting the Apex, but Postponing Justice

The STCAU’s Statute distinguishes itself from the instruments of other “internationalised” mechanisms in at least two respects, which, taken together, expose a foundational contradiction.

First, the STCAU’s Statute imposes a more precise and aspirational ambit than the Rome Statute of the International Criminal Court or the statutes of other internationalised tribunals. The purpose of the STCAU, per Article 1, is “to investigate, prosecute and try persons who bear the greatest responsibility for the crime of aggression against Ukraine.” The Rome Statute, by contrast, has a broader jurisdiction ratione personae that extends to “persons for the most serious crimes of international concern”. Of the “internationalised” courts, the jurisdictional formulation in the Statute of the Special Court for Sierra Leone (SCSL) is the closest to that of the STCAU in focusing on individuals “who bear the greatest responsibility for serious violations.” However, the SCSL Statute, like all internationalised courts and the Rome Statute prior to the Kampala Amendment, did not include the crime of aggression within its mandate, thus limiting its comparability here.

The narrowing of personal jurisdiction in the STCAU State to those at the apex of decision-making authority over the crime of aggression arguably duplicates the elements of the crime itself — which, under Article 2(1), requires the “planning, preparation, initiation or execution” of aggression by someone in a position to effectively exercise control over or direct “the political or military action of a State”. Article 1 reflects RBIO’s influence because it inflates legal language to serve political optics. For the drafters of the STCAU, seeking accountability for anyone who satisfies these elements of the crime is secondary to the symbolic impact of targeting those at the top of the ladder.

The language of Article 1 makes the second feature of the STCAU Statute all the more striking. Despite its explicit focus on holding those with the “greatest responsibility” accountable for the crime of aggression, Article 23(5) grants absolute personal immunity to sitting heads of state, heads of government, and foreign ministers — in other words, precisely the individuals most likely to meet that threshold.

In domestic law, personal immunity shields these high-ranking officials from the jurisdiction of domestic courts, as affirmed by the International Court of Justice in the Arrest Warrant case and supported by decisions in domestic courts. This immunity does not extend to international courts, as it derives from sovereign equality among states, which does not apply to international judicial bodies. The STCAU, however, codifies it directly into its statutory framework at Article 23(5), which reads:

Where the indictment concerns a head of State, head of government or minister of foreign affairs, the Pre-Trial Judge shall not confirm the indictment and shall order the proceedings be suspended until that person no longer holds that office or an appropriate waiver has been presented to the Special Tribunal. During the suspension, the Pre-Trial Judge shall not otherwise act upon the indictment.

Article 23(5)’s codification of personal immunity stands in stark contrast to the statutes of predecessor courts, which have often explicitly stated that such immunities will not bar jurisdiction (see, for example, Article 27(2) of the Rome Statute). More fundamentally, it also marks a departure from the very origins of the crime of aggression, as found in the 1919 Commission on the Responsibility of the Authors of the War and on Enforcement of Penalties, which rejected the idea that heads of state could enjoy immunity for perpetrating a war of aggression, on the basis that such impunity would “shock the conscience of civilized mankind.”

In today’s global context, the consequences are profound. The individuals who likely bear the “greatest responsibility” for the crime of aggression against Ukraine are entrenched “strongmen.” They do not preside over functioning democracies where free and fair elections might offer a path to their removal, nor do they lead collapsing regimes on the verge of implosion. They are authoritarians who have consolidated domestic power and will only relinquish it upon death or total regime collapse. A recent New York Times exposé provides a timely reminder that entrenched leaders may even weaponize war itself as a means of staying in power.

The deferral of justice, enshrined in Article 23(5), is not a temporary delay of justice. It may be, for these actors, a virtual guarantee of lifelong immunity.

The STCAU: An International(ised) Tribunal? RBIO and the Blurring of Legal Categories

Taken together, Article 1 and Article 23(5) establish a contradiction: while the STCAU is tasked with identifying and prosecuting those bearing “the greatest responsibility” for aggression against Ukraine, it simultaneously erects a procedural shield around many of those very perpetrators.

A central question becomes: does the STCAU qualify as an “international court” for the purposes of international law? More specifically: could the STCAU have lawfully set aside personal immunities ordinarily accorded to high-ranking state officials under customary international law? 

The question of whether the STCAU qualifies as an “international court” in the classical sense — in which personal immunities could be avoided — further underscores RBIO influence. The STCAU’s institutional design resists classification. It was not established through a multilateral treaty regime (as with the ICC) or pursuant to the Security Council’s Chapter VII mandate (as with the ICTY or SCSL), where jurisdiction is more clearly rooted in collective state consent (see Robinson et al, p. 498, and Mullin and Stantin; more generally, see Sadat). Yet its structure, mandate, and origins as a court built by a coalition of states place it well beyond the scope of a purely domestic court operating with foreign assistance.

Kevin Jon Heller has argued that there is “no argument that a [tribunal for aggression] created by the Council of Europe and Ukraine qualifies as ‘international’ within the meaning of [the] Arrest Warrant case.” But the inclusion of Article 23(5) clearly signals the tribunal’s aspiration to some form of international competence. If the STCAU regarded itself as anything other than an international court, the issue of immunities for foreign officials would surely be irrelevant. At the very least, its statutory language signals that the tribunal occupies a legally ambiguous space that is not as clear-cut as Professor Heller would suggest.

The STCAU’s ambiguity is a hallmark of RBIO’s fragmentation, in which the terms of the game are dictated by political whim. RBIO blurs legal typologies — between international, internationalised, hybrid, and domestic courts — and allows political expediency to shape the jurisdiction of tribunals in ways that depart from precedent and conventional international law. 

Article 23(5)’s Impact: A Pragmatic Concession or Entrenching Impunity?

I appreciate that “the strongman’s clause” was a necessary political compromise. According to the Asser Institute’s assessment of the STCAU’s Statute, Article 23(5) was the culmination of a paper coauthored by Germany and — to no surprise to subscribers of the RBIO thesis — the United States. This qualification was essential to securing the diplomatic support and votes required for the tribunal’s creation. Without it, the STCAU would not have come into existence at all. 

Viewed from this angle, Article 23(5) is a pragmatic concession which offers the prospect of accountability for many potential perpetrators who do not fall within the personal immunity troika. In that sense, the STCAU is not unlike other international(ised) courts, all of which are built on compromise. Such trade-offs are, to some extent, inherent to the system.

This rationale, however, reflects the troubling logic of the RBIO, which permits legal innovation only insofar as it accommodates political interests, and at the cost of undermining core legal norms and the legitimacy of international justice as a whole. Some of the most significant advances in international justice have stemmed from creative efforts to reconcile the law with political reality, but that creativity has always been rooted in principle; it has built upon precedent or, at the very least, departed from it in a reasoned and principled way.

In this light, Article 23(5) is a clear expression of the structural tension between the RBIO and the post-war legal order it is slowly supplanting. It signals a shift toward an international legal architecture increasingly shaped by political calculus, rather than coherent, universally applied principles. The result is not merely an exception to the rules — it is rewriting the rules themselves.