For over a decade, the International Criminal Court (ICC) has maintained the position that heads of state do not enjoy immunity from prosecution for atrocity crimes before international courts. This stance, most notably articulated in the Court’s 2019 Appeals Chamber judgment concerning Sudan’s then-president Omar al-Bashir, asserted that customary international law permits the arrest and surrender of a sitting head of state by other states, even absent a waiver of immunity. The ruling significantly shaped the Court’s approach to questions of personal immunities under articles 27 and 98 of the Rome Statute. However, evolving evidence of state practice and the ICC’s recent issuance of arrest warrants against Russian President Vladimir Putin and Israeli Prime Minister Benjamin Netanyahu have brought renewed attention—and controversy—to the legal and political sustainability of this position.
As recent commentary, including Ward Ferdinandusse’s detailed analysis on Just Security, has underscored, the ICC’s legal reasoning is undergoing renewed examination, including in the context of ongoing discussions concerning the authority of a potential Special Tribunal on the Crime of Aggression on Ukraine. The discourse now centers not solely on whether international law permits the prosecution of sitting heads of state, but whether the ICC’s approach remains consistent with state behavior and contemporary legal understandings. In this shifting context, it is timely to reflect on whether the ICC’s approach to head-of-state immunity remains sustainable—or whether a thoughtful recalibration could enhance the Court’s effectiveness and credibility.
Reexamination of past precedent would make the Court stronger at a moment when a perceived gap between its claimed authority and the enforceability of its decisions threatens to undermine the broader project of accountability on which the Court stands. There are pathways for the Court to recalibrate its legal reasoning—particularly regarding head-of-state immunity—without abandoning its commitment to justice. By anchoring its decisions more firmly in customary international law and the realities of state cooperation, the ICC can reinforce its credibility, improve compliance with arrest warrants, and foster renewed diplomatic support. At a time when major powers are increasingly skeptical of international institutions, strengthening the Court’s legal coherence is not merely a technical correction—it is a diplomatic necessity for preserving the legitimacy of the international criminal justice system as a whole.
The Limits and Controversy of the Bashir Decision
A reassessment of this issue necessitates revisiting the ICC Appeal Chamber’s judgment in the Bashir case. At the time, the Appeals Chamber held that under customary international law, heads of state do not enjoy immunity before international criminal tribunals—distinguishing them from national courts, where such immunity remains uncontested—, including, in the Chamber’s view, the ICC. This decision marked a significant assertion of international criminal accountability but also provoked robust debate. As Ferdinandusse observed, the ruling was the subject of extensive analysis and critique, with even many supporters acknowledging ambiguities in its reasoning (see e.g. here (D. Akande), here (D. Jacobs), here (B. Batros)).
Critiques of the decision are multifaceted. They include the Appeals Chamber’s misreading of the International Court of Justice’s Arrest Warrant case, its selective interpretation of relevant Security Council resolutions, and its seeming disregard for extensive contrary state practice. Further, instead of a single, cohesive judgment, the decision was accompanied by a separate opinion from four (of five) judges and a Court-issued Q&A document that appeared to introduce additional or even contradictory reasoning and whose authorship remains unclear.
Perhaps most important, as Ferdinandusse chronicles, is the mounting evidence in the years since the decision—from states across Europe, Africa, Asia, and the Americas—that undercuts the notion that there exists widespread state practice and opinio juris supporting the Court’s position. Rather than demonstrating a clear customary norm, the behavior of states suggests that head-of-state immunity remains a deeply embedded feature of international legal relations, or at minimum one where state practice is more fragmented vice widespread.
A central concern with the Bashir decision lies not only in its specific legal conclusions but in the broader methodological approach it reflects—one that has become increasingly prevalent in the field of international criminal law. At the heart of the issue is a recurring tendency, observed among both international jurists and academic commentators, to treat prior judicial decisions—particularly those of international or hybrid tribunals—as primary evidence of customary international law. This approach, while understandable given the limited availability of other sources, risks conflating judicial reasoning with state-driven legal development.
Customary international law, by definition, derives from two elements: state practice and opinio juris—the belief that such practice is carried out as a matter of legal obligation. Accurately identifying a customary norm requires a rigorous empirical analysis of how states behave and what they expressly regard as legal duties. However, in the field of international criminal law, there has been a discernible drift toward relying on the jurisprudence of prior courts as a proxy for this empirical analysis. While international judicial opinions can offer persuasive insights and shape normative expectations, they are not a substitute for the evidence of actual state conduct and belief.
The Bashir ruling exemplifies this tendency. Rather than undertaking a comprehensive survey of state practice and opinio juris across relevant jurisdictions, the Appeals Chamber leaned heavily on the jurisprudence of earlier tribunals—such as the SCSL, ICTY, ICTR, and even the post-World War II trials (see joint concurring opinion, cited in the main judgment)—to assert the non-applicability of head-of-state immunity before international courts. These decisions, while important, reflect the reasoning of judicial bodies rather than the broader consensus or consistent behavior of states. Moreover, none of these tribunals undertook a systematic methodology to establish customary international law through an analysis of both state practice and opinio juris, particularly on the precise matter at issue in the Bashir decision concerning head of state immunity. As a result, the ruling presents a doctrinal assertion that may lack sufficient grounding in the two elements necessary to constitute customary international law.
This methodological pattern has persisted in much of the subsequent defense of the Bashir decision. Prominent scholars such as Leila Sadat and former ICC judge Chile Eboe-Osuji (also an author of the Bashir decision) have pointed to prior tribunal jurisprudence as central to their justifications for the ICC’s stance. While these perspectives offer principled arguments in favor of accountability, they often mirror the same evidentiary shortcomings—emphasizing legal reasoning over empirical state behavior.
Legal Fragmentation and the Risk to the ICC’s Authority
Beyond the core legal questions surrounding immunity, more systemic concerns loom in the ICC’s approach. First is the risk of fragmentation in the international legal order. Regional bodies, such as the African Union and the Arab League, have long expressed apprehension over what they perceive as the uneven application of international criminal law—particularly when prosecutions appear to disproportionately target leaders from the so-called “Global South”. These critiques reflect not only regional grievances but also deeper questions of legitimacy, equity, and the potential politicization of justice.
Recent prosecutorial decisions have only intensified this scrutiny. The issuance of arrest warrants for Israeli leaders, following similar action against Russian President Vladimir Putin, has prompted speculation that the Court is attempting to demonstrate balance in response to longstanding accusations of selective justice. While the legal basis for each case must be assessed on its own merits—and the decisions may be justified by the unprecedented nature of both conflicts—, the sequencing and political context of these decisions raise broader perception challenges: namely, whether the Court is acting out of legal necessity or in response to pressures on its institutional legitimacy, and whether Prosecutor Khan’s charging decisions are guided more by legal principle or political calculation.
These perceptions feed into a more troubling trend: the erosion of respect for the Court’s authority. Some states have openly defied ICC decisions with minimal consequence. For example, Mongolia’s decision not to arrest Putin during his visit was met with little more than symbolic criticism by the Assembly of State Parties (ASP). Such instances, though often justified on legal or political grounds, send a collective signal that the Court’s authority can be disregarded without meaningful repercussions. Overall, reactions to ICC arrest warrants—especially those targeting high-level officials—reflect a fragmented landscape. While some states have affirmed their commitment to cooperation, others have either remained silent or publicly opposed the Court’s actions, often invoking competing interpretations of immunity or political sensitivities. This split underscores not only the legal complexity surrounding these issues but also the broader challenges the ICC faces in securing consistent, principled support from the international community.
The Dangerous Gap Between Claimed Authority and Enforceability
This institutional dilemma was sharply illustrated in a recent exchange between legal scholars Mark Freeman and Mark Drumbl. Freeman observed that the ICC’s most significant existential threat may not come from external political opposition, but from within—through a slow erosion of credibility when its decisions lack enforcement. Drumbl echoed this concern, cautioning that when the Court advances legal positions that outpace international consensus or extend beyond accepted doctrine, it risks both political backlash and doctrinal marginalization.
Their exchange underscores a fundamental point: the problem is not ambition, but disconnection. The ICC’s pursuit of accountability must remain principled, but it also must remain grounded in legal clarity and practical enforceability. When the Court asserts far-reaching legal interpretations without securing the political or doctrinal support necessary to implement them, it undermines the very authority it seeks to project. The risk is that the Court becomes mired in pronouncements in search of enforcement, where symbolic action substitutes for actual accountability.
This tension lies at the heart of the ICC’s mandate. The Court may declare that head-of-state immunity does not apply before international tribunals, but such assertions are only effective if states are willing to act on them. The danger is not isolated noncompliance—it is the normalization of disregard. As more states openly question the Court’s legitimacy or refuse to cooperate, future enforcement becomes even more elusive.
This dynamic echoes the enduring insight from Marbury v. Madison, where Chief Justice John Marshall cautioned that a legal ruling without the means of enforcement is little more than a declaration without power. The ICC faces a similar dilemma today. In some respects, it may have attempted to assert its own Marbury moment prematurely—staking a bold legal claim without the institutional or political foundation necessary to support it. The Court’s future effectiveness will hinge not only on the strength of its legal convictions, but on its ability to translate those convictions into outcomes that resonate beyond the page. If that gap between authority and enforceability remains unaddressed, the ICC risks weakening the very justice it was created to uphold.
Structural constraints of the ICC itself compound this challenge. Unlike domestic courts, the ICC operates without a centralized enforcement mechanism and depends almost entirely on the voluntary cooperation of states. This reliance leaves the Court vulnerable to political resistance—particularly when states view its actions as exceeding legal bounds or lacking consistency. In such cases, states may simply decline to enforce arrest warrants or publicly reject the Court’s jurisdiction, further straining its credibility.
Pathways for Reconciliation: Strengthening Legal and Political Alignment
This is not a call for retreat, but for recalibration. The ICC must strive to align its legal interpretations with rigorous analysis of evolving state practice and a realistic assessment of political conditions. International justice requires both normative strength and institutional credibility.
One constructive avenue would be to foster enhanced dialogue among states through the ASP, including the creation of a dedicated working group to examine contemporary state practice and develop clearer guidance on head-of-state immunity. Such a process could help promote greater legal coherence and shared expectations among member states. Crucially, it would also reaffirm the role of states as the primary architects of the Court’s legal framework—ensuring that the development of key norms remains anchored in the ASP’s legislative mandate, rather than being shaped exclusively through judicial interpretation.
Another potential avenue is closer engagement with the United Nations Security Council. While the ICC has historically maintained its independence from political bodies, strategic collaboration with the Security Council—particularly when issuing arrest warrants for sitting heads of state—could provide additional legal clarity and enforcement mechanisms. Security Council resolutions explicitly removing immunity could help bridge the gap between legal theory and state practice. Some may argue that involving the Security Council risks politicizing the Court’s mandate. However, this engagement can also serve to ground the Court’s actions within the framework of global political realities, ensuring that there is sufficient international backing for enforcement. In contexts where state cooperation is often elusive, Security Council involvement can lend critical political weight and legitimacy to ICC decisions, increasing the likelihood of compliance and reinforcing the Court’s authority on the global stage.
Furthermore, the ICC’s Office of the Prosecutor (OTP) could adopt a more pragmatic strategy by prioritizing cases with a higher likelihood of enforcement. Prosecutor Karim Khan has previously emphasized the importance of securing arrests to maintain the Court’s credibility (despite seemingly departing from that campaign promise). Ensuring that the ICC’s efforts result in tangible legal consequences, rather than unexecuted warrants, would strengthen both its legitimacy and deterrent effect.
Finally, the Court itself should recognize the flexibility within its institutional structure to correct course. There is no rule that precludes an Appeals Chamber of the ICC from departing from a prior Appeals Chamber decision. As many readers will know, the ICC does not operate under a doctrine of stare decisis. While precedent can play a persuasive role, it does not bind future panels of judges in different cases. Historically, the Court has often comported with earlier rulings for the sake of consistency, but it retains the institutional discretion to deviate when legal or factual circumstances demand reassessment. Revisiting the Bashir precedent through a new Appeals Chamber decision would not violate the Court’s procedures—it would demonstrate its willingness to evolve in light of shifting legal realities and state practice.
A decision to reverse the Bashir precedent would undeniably carry significant practical and political consequences. It would cast uncertainty over existing arrest warrants against sitting heads of state, potentially undermining the legal basis on which they were issued. Such a move would likely be welcomed by some states that have long been critical of the Court’s approach to immunity—but deeply unpopular among others, especially those that have supported the ICC’s efforts to hold powerful leaders accountable. Most notably, it risks alienating victim communities who view these warrants as a vital recognition of their suffering and a rare act of international accountability.
These concerns deserve serious consideration. Reversal must not be seen as a retreat from justice or a concession to political expediency. Rather, it should be framed as a principled recalibration—an effort to bring the Court’s jurisprudence into closer alignment with customary international law and to reinforce the legitimacy of future prosecutions. Upholding flawed legal reasoning for fear of political fallout risks weakening, rather than preserving, the Court’s authority. Victim communities are best served by a Court that commands credibility, even if doing so requires difficult institutional self-correction. In the long term, the ICC’s moral and legal authority depends not on symbolic gestures, but on the integrity and coherence of its legal foundations. Indeed, as observers of international criminal trials know well, the trajectory of international criminal justice is rarely linear. The recent arrest and extradition of Rodrigo Duterte is a case in point: while the path to accountability may be slow and contested, the eventual engagement of legal institutions reflects the enduring force of justice.
Critics may also claim that a reversal would be seen as capitulating to political pressure. But it is precisely the opposite. A decision to reverse course—made transparently, based on sound legal analysis, and rooted in an honest assessment of the law and state practice—demonstrates the Court’s independence. Capitulation would mean clinging to a position that is no longer legally defensible, for fear of political optics. A principled adjustment, on the other hand, signals maturity and integrity.
A Critical Moment for the Future of International Justice
The ICC stands at a crossroads. As recent state reactions demonstrate, the Court’s stance on head-of-state immunity is far from universally accepted, and its ability to enforce arrest warrants against sitting heads of state remains in question. While the principles underlying the Bashir decision remain compelling, the practical realities of state practice and enforcement necessitate a reassessment of the ICC’s legal framework.
Reconsidering the Court’s position does not entail abandoning the cause of justice. On the contrary, it reflects a commitment to ensuring that international criminal accountability is pursued on a foundation that is both legally sound and institutionally resilient. By engaging openly with states, clarifying legal principles, and aligning its strategies with enforceable outcomes, the ICC can continue to uphold its mission while adapting to the complex environment in which it operates.
Such a recalibration would not signal weakness, but strength—a willingness to evolve, to listen, and to lead with integrity in the service of justice.
– Nema Milaninia (LinkedIn – X) is a partner at King & Spalding LLP. Published courtesy of Just Security.
