The French Court of Cassation Endorses Head of State Absolute Personal Immunity from Foreign Jurisdiction

[Miguel Lemos is an Assistant Professor at the Faculty of Law, University of Coimbra]

On 14 November 2023, a French court issued an arrest warrant for Syria’s President Bashar al-Assad on “charges of complicity in crimes against humanity and complicity in war crimes”. On 26 June 2024, this decision was upheld by the Court of Appeals of Paris. The prosecutor-general at the Paris court immediately filed an appeal against this ruling to the French Court of Cassation, the highest judicial authority in France. At the Court of Cassation, there was an order for the immediate examination of the appeal. Considering the delicate nature of the issue, the appeal was referred to its “plenary assembly”. On 25 July 2025, the court issued its judgment.  

The judgment was awaited with great expectation. Many hoped it would constitute a landmark decision in the ‘fight against impunity’. As put by Dan Plesch and Steve Kostas, “justice must prevail over impunity”. To that effect, they urged the Court of Cassation to consider “rediscovered” Second World War evidence, particularly, Polish, Czechoslovak and Belgian indictments against Adolph Hitler, and their endorsement by the United Nations War Crimes Commission (UNWCC). According to Plesch and Kostas, this and other Second World War evidence reveal “extensive, coordinated state practice … explicitly rejecting head of state immunity for international crimes”.     

Second World War Evidence Ignored 

The Court of Cassation did not consider such evidence. In doing so, it joined the long list of those who, during the past two decades, have overlooked the significance of that evidence. Such list includes: all judges of the International Court of Justice in the Arrest Warrant case; all those who elaborated or contributed to the twenty-six reports of the International Law Commission and its Special Rapporteurs on the issue of immunity of foreign officials; all judges and prosecutors of the International Criminal Court who intervened in cases where immunity of foreign officials was an issue; all most prominent experts in international law who, in Jordan Referral Re Al-Bashir, intensely discussed that issue; and the overwhelming majority of scholars who wrote about the issue since the Arrest Warrant.    

The fact that the Court of Cassation did not consider such evidence is particularly noteworthy because, while all those included in that list were apparently not even aware of that evidence, the Court of Cassation was. It heard about it during the oral hearings on a related case, Dan Plesch provided the court with a memorandum dissecting it, and the Rapport du Conseiller of the court also alluded to it. While not considering that evidence, the court easily distanced itself from its own past position. 

Back in 2001, the Court of Cassation had suggested that there were indeed exceptions to head of state personal immunity from foreign jurisdiction. Candidly, the court recognized this fact. However, it stressed that it had “never recognised” any specific exception “in practice”, and noted it had not yet pronounced in cases involving crimes against humanity or war crimes. The court’s new pronouncement removes all past ambiguity. It ruled that international crimes “are not exceptions to the principle of immunity from jurisdiction of foreign Heads of State-In-Office”.  

In this post, I will not analyse the court’s rationale and its main ruling. This is because the court basically replicates the arguments long put forward by the International Court of Justice and the International Law Commission to justify the existence of an absolute head of state personal immunity from foreign jurisdiction. Instead, I will focus on the reasons which led the court not to consider that Second World War evidence, and on the consequences of its ruling for the “current state of international organization”. 

Why did the Court not Consider Second World War Evidence?

As to those reasons, because the court did not provide a justification for not even mentioning such evidence, one can only speculate. The following words of the rapporteur of the court might be a good starting point: 

Abstraction faite de la question des crimes commis durant la seconde guerre mondiale, il n’a pas été identifié de décision d’une cour suprême étrangère admettant une limitation de l’immunité personnelle en cas de crimes internationaux (emphasis added).

My translation: “Setting aside the question of crimes committed during the Second World War, no decision by a foreign supreme court has been identified that recognises a limitation to personal immunity in cases of international crimes”. 

Following on the footsteps of its rapporteur, the court also set aside that question. This ‘set aside’ is particularly interesting in light of the fact that, in what concerns the Second World War, the French were the strongest advocates of the position that head of state immunity did not bar prosecution by foreign domestic courts.  

The obvious question is: why? Why did the court set aside the question of crimes committed during the Second World War? My unsubstantiated guess is that both its rapporteur, and then the court itself, chose not to confront head-on an idea that is popular today. Namely, that the ‘victor’s justice’ delivered eight decades ago in Nuremberg translated into many contortions to fundamental principles of criminal law and international law. 

Of course, I am thinking of the criminal law principle of legality, and the centuries-old and “not controversial” principle granting heads of state a “full immunity” from foreign jurisdiction. According to a widespread account, this full immunity principle has been a feature of international law from “time immemorial”. If such widespread account is sound, the fact that the sixteen countries which formed the UNWCC endorsed the view that Hitler was not entitled to personal immunity only means that those countries were prepared to violate that centuries-old principle. 

However, as I argue in an article published this October in the Leiden Journal of International Law, the idea that heads of state have for centuries enjoyed an absolute immunity from foreign jurisdiction is a “21^st century myth”. According to such argument, those countries could not be prepared to violate a rule of international law that did not exist at the time. 

But let us assume that my argument is flawed and, hence, that rule existed at the time. In fact, while the indictments against Hitler were “grounded on a belief” that such rule did not exist, some jurists who were involved in the work of the UNWCC believed it did. In the History of the United Nations War Crimes Commission, the authors of this important publication consistently expressed the view that the demarches of the UNWCC represented a ‘rejection’, ‘discard’, ‘replacement’ of the previous rule that shielded heads of state from prosecution in foreign countries. As such, according to that publication, such demarches and other developments “brought about profound alterations” in the doctrine of immunity of heads of state.     

Even if the view of the authors of this publication represented a correct analysis of the changing nature of the law at the time (it did not), the fact is that the Nuremberg International Military Tribunal pronounced itself in the sense that such immunity doctrine did not apply to “acts which are condemned as criminal by International Law”. As I also argue in that Leiden Journal of International Law article:

The no-immunity position of the IMT is a ‘principle’ identified in the IMT Judgment. The ‘principles’ identified by the IMT either reflected customary law or … turned into customary law when the states of the United Nations unanimously endorsed them soon after the IMT Judgment was delivered. In December 1946, the General Assembly affirmed ‘the principles of international law recognized by the Charter of the Nurnberg Tribunal and the judgment of the Tribunal’. This endorsement by the vast majority of the existing states in 1946 is an expression of the view of the international community at the time. … [I]t was therefore well established in 1946 that heads of state were not entitled to immunity with regard to aggression and other war-related crimes.

Assuming that this argument is sound, one needs a compelling explanation on how that 1946 Nuremberg no-immunity principle turned into the absolute immunity principle upheld by the International Court of Justice in 2002, and by the French Court of Cassation this past July 2025. 

Consequence of the Judgment for the Current State of International Organization

Arguably, such compelling explanation now exists. That might be the most important consequence of the Court of Cassation’s ruling for the current state of international organization, and for present-day debates about the prosecution of heads of state, heads of government, and foreign ministers who might be responsible for international crimes. Indeed, today, there are two crucial facts which are apparently conveying us a clear message. 

The first fact is that the Court of Cassation overruled the no-immunity position of the Court of Appeals of Paris and backtracked from its own previous position. This means that, at this moment in time, there is no longer any important judicial authority which, expressly or implicitly, rejects the customary law status of the absolute personal immunity principle set out in the Arrest Warrant. Even South Africa’s Supreme Court does not reject this status, albeit it curiously declared that South African law’s “departure” from that principle is a matter of “national pride rather than concern”. 

The second fact is that a very large number of countries have now pronounced themselves formally on the topic of immunity of foreign officials: 

From November last year to January this year, all countries which submitted their comments and observations to the ILC on … [this] topic …  endorsed without exception – or, at least, did not in any way challenge – the position adopted by the ICJ in the Arrest Warrant case… Even Poland – which ‘reminded’ de ILC of its indictments against Hitler – did not challenge the absolute personal immunity of heads of state ruling put forward in the Arrest Warrant.  

In short: today, it is manifest that states and courts are of the opinion that the absolute immunity ruling set out by the ICJ reflects current customary international law. This suggests that state practice which is contrary to the 1946 Nuremberg no-immunity principle has reached a “critical mass”. As Theodor Meron explains, there is a point at which state practice contrary to a previous customary rule is so voluminous “that the norm in question cannot be said to be customary”.

In other words, it seems no longer tenable to hold on to the position of a minority of scholars, including myself, who have been maintaining that, despite the “non-sense”, “unfortunate”, and “hair-raising” decision of the ICJ in the Arrest Warrant, heads of state are actually not entitled to an absolute personal immunity from foreign jurisdiction. Perhaps ironically, this means that today there are less paths to hold accountable those normally most responsible for international crimes than in 1946. Ironic as that might be, that is where we are. And that is so, at least until the day where a “revival” of the position of the International Military Tribunal opens the path for a return to that Nuremberg “most important” no-immunity principle.