I. Introduction

On 24 February 2021, a German court in Koblenz sentenced Eyad Al-Gharib, a Syrian national, to four and a half years in prison for aiding crimes of torture and aggravated deprivation of liberty in Syria. The case was prosecuted in Germany under universal jurisdiction. In convicting Al-Gharib, the Koblenz court relied on definitions of crimes against humanity that reflect those found in the ICC Statute. However, the court relied on a domestic mode of liability to connect Al-Gharib to these crimes.

In this blog, we consider whether the use of domestic modes of liability in universal jurisdiction cases is consistent with the principle of legality. International law determines what crimes can be prosecuted based on universal jurisdiction. Accordingly, the definitions of crimes and modes of liability applied in universal jurisdiction cases should reflect international law. Otherwise, courts might violate the principle of legality by retroactively punishing conduct which was not criminalised at the time it occurred. In part II of the blog, we briefly outline how this issue arose in the recent Koblenz case of Al-Gharib. In part III, we examine what modes of liability should apply in universal jurisdiction cases considering the principle of legality. We then apply this reasoning to Al-Gharib’s case. Finally, in part IV, we conclude with some additional thoughts on the application of domestic modes of liability in universal jurisdiction cases.

While our focus is on modes of liability, the discussion here raises broader questions about the principle of legality and applicable law in universal jurisdiction cases. Universal jurisdiction cases are becoming increasingly common. Almost one year after Al-Gharib’s prosecution, on 13 January 2022, the Koblenz court sentenced Anwar Raslan to life imprisonment for committing crimes against humanity in Syria. Another recent example includes the prosecution of Alieu Kosiah in Switzerland. The integrity of such cases depends on the ability of domestic courts to provide individuals with a fair trial.

II. Eyad Al-Gharib’s case

For the purpose of this blog, Al-Gharib’s case is notable for two reasons.

First, Al-Gharib’s case is an example of ‘pure’ universal jurisdiction. Pure universal jurisdiction is not based on multi-lateral treaties.1 Instead, this jurisdiction ‘is criminal jurisdiction based solely on the nature of the crime, without regard to where the crime was committed, the nationality of the alleged or convicted perpetrator, the nationality of the victim, or any other connection to the state exercising such jurisdiction’ (Princeton Principles, p. 28). States may exercise pure universal jurisdiction over ‘serious international crimes as defined by international law’ that affect the values of the international community (Institute of International Law, p. 1). The serious international crimes over which states can assert this jurisdiction include genocide, crimes against humanity, and war crimes.2

In convicting Al-Gharib, the Koblenz court relied on Section 1 of the German Code of Crimes against International Law (Völkerstrafgesetzbuch, hereafter VStGB) which allows German courts to prosecute international crimes through universal jurisdiction. Al-Gharib is a Syrian national who was found guilty of assisting crimes of torture and aggravated deprivation of liberty in Syria against Syrian victims. Syria ratified the Convention Against Torture (CAT) in 2004 but is not a member of any treaty that criminalises aggravated deprivation of liberty. Consequently, the Koblenz court could have exercised jurisdiction to prosecute torture crimes based on Article 5 of CAT. Because Syria is not a party to the ICC Statute or any other treaty that would provide a German court with jurisdiction to prosecute the deprivation of liberty as a crime against humanity, the Koblenz court could only prosecute Al-Gharib for this crime based on pure universal jurisdiction.  

Second, Al-Gharib’s case is an example of the use of domestic modes of liability in universal jurisdiction cases. According to the VStGB, German courts have jurisdiction to prosecute international crimes. The VStGB incorporates parts of the ICC Statute into German domestic law. For the most part, the VStGB sets out the definitions of international crimes found in the ICC Statute. The ICC’s definitions of crimes largely, but not entirely, reflect customary international law. The VStGB also sets out individual criminal responsibility for perpetrators and responsibility of military commanders, but it does not mention any other modes of liability found in the ICC Statute. Consequently, for modes of liability like aiding and abetting, German courts turn to the German Criminal Code (Strafgesetzbuch, hereafter, StGB) which defines and regulates national crimes.

Al-Gharib was found guilty of aiding international crimes. German secondary liability is set out in articles 26 and 27 of the StGB. Aiding, found in Article 27, applies to anyone who ‘intentionally assists another in the intentional commission of an unlawful act’. The mens rea requirement under Article 27 is a ‘knowledge of risk’ or dolus eventualis standard (Aksenova, p. 27). By contrast, the mens rea standards for aiding and abetting under customary international law (arguably knowledge or dolus indirectus) and under the ICC Statute (arguably, purposive intent or something closer to dolus directus) are both higher thresholds than the German requirement of recklessness.3

In part III, we examine whether courts should rely on domestic modes of liability in pure universal jurisdiction cases in light of the principle of legality. Aside from the lower mens rea threshold, the German definition for aiding is analogous to definitions of aiding and abetting relied upon at international courts and tribunals. Still, the difference between the two mens rea thresholds could be the difference between guilt or innocence.4 The principle of legality can guide our assessment of whether the application of a domestic mode of liability is permissible in universal jurisdiction cases.

III. What modes of liability should courts apply in universal jurisdiction cases?

The principle of legality requires that crimes and punishment are defined by law. This tenet of criminal law and rule of customary international law protects individuals against retroactive and arbitrary punishment. The principle is violated if an individual is convicted for conduct that was not criminalised by law at the time that it occurred. Moreover, law that criminalizes conduct must be foreseeable and accessible to an accused. Importantly, international courts and tribunals have found that modes of liability are subject to the principle of legality. A conviction can only be based on a mode of liability that was applicable to the accused at the time of their alleged criminal act, and the mode of liability must be sufficiently foreseeable and accessible to the accused (Duch, ECCC para. 96; Ojdanić, ICTY para. 37; Jurisdiction Appeal Decision, KSC para. 211). 

Universal jurisdiction is generally understood as criminal jurisdiction based solely on the nature of the crime. States can exercise universal jurisdiction over serious international crimes that ‘affect the fundamental interests of the international community as a whole’ (Princeton Principles, p. 23). Consequently, the scope of universal jurisdiction is determined by the subject-matter upon which it is based. While states may prescribe law and adjudicate cases based on universal jurisdiction, no single state has the power to determine what conduct is criminalised under this jurisdiction. Indeed, the purpose of universal jurisdiction would be undermined if states could assert such jurisdiction over so-called ‘international’ crimes that are substantively different to their customary international law eponym. Instead, international law, being the law of nations, determines the subject matter of universal jurisdiction, including what crimes and modes of liability a state can prosecute. In the absence of a central legislative body at the international level, sources of international law are varied. Customary international law is the only available source of international law that can determine what acts are criminalised in pure universal jurisdiction cases. In sum, because international law confers upon states the ability to exercise universal jurisdiction over serious international crimes, it follows that international law should define those international crimes and the corresponding modes of liability that can be prosecuted through this jurisdiction (Colangelo, p. 150).

In most universal jurisdiction cases, customary international law and foreign domestic law (i.e., the law of where the conduct occurred) are the only sources of law that applied to the accused when their conduct occurred. However, when adjudicating these cases, as in Al-Gharib’s case, domestic courts often rely on domestic law to prosecute individuals. In doing so, these courts substitute (either advertently or inadvertently) their domestic law for the international law that was applicable to the accused. This is referred to as ‘retroactive recharacterization’. Retroactive recharacterization is permissible in international law within reason, but it is not without risks to the principle of legality. As Dias notes, when courts retroactively recharacterize international law as domestic law, they risk changing the substantive content of the law to the detriment of the accused (p. 658).  A domestic court will violate the principle of legality if it convicts an individual through universal jurisdiction by relying on its own domestic law that neither applied to the accused’s acts when they occurred nor reflects the international law which applied to the accused’s acts. Thus, to avoid violating the principle of legality in pure universal jurisdiction cases, courts should ensure that any domestic laws which are decisive to criminal prosecution or punishment, including modes of liability, adequately reflect customary international law (Dias, pp. 72, 73).

Given that Al-Gharib was prosecuted under universal jurisdiction in Germany, the Koblenz court should have applied law that, at the very least, reflects customary international law.5 German law did not apply to Al-Gharib when he carried out the acts for which he was subsequently prosecuted. To the best of our knowledge, only Syrian law and (customary) international law applied to Al-Gharib at the time when his acts occurred. No other legal basis criminalised his actions in Syria, against Syrian victims.

Nonetheless, the German court applied German domestic law in Al-Gharib’s case. While some of this domestic law incorporated international law, namely the crimes in the ICC Statute, the Koblenz court also relied on domestic law that was not intended to reflect international law, namely the law on assistance liability in Article 27 of the StGB. The court did not consider whether this domestic law aligns with customary international law. Aiding, as a mode of liability under German law, was central to Al-Gharib’s prosecution. By implicitly substituting domestic law for customary international law, the Koblenz court retroactively recharacterized the applicable mode of liability under customary international law, aiding and abetting, as aiding under German law.

The Koblenz court’s reliance on German law raises the question of whether the court violated the principle of legality. On the one hand, all persons should have a reasonable expectation that they can be prosecuted for assisting an international crime. International courts have found that the principle of legality will not be violated so long as interpretations of the law are foreseeable and accessible. Interpretations should be ‘consistent with the essence’ of the law (Jorgic, ECtHR, para. 100; Vasiliauskas, ECtHR, paras 155-161) or ‘within reasonable limits of acceptable clarification’ (Ojdanić, ICTY para. 38). Additionally, the principle of legality allows for the progressive development of law (Ojdanić, ICTY para. 38; Jurisdiction Appeal Decision, KSC para. 214). Aiding under German law is, for the most part, consistent with the essence of the aiding and abetting under customary international law. Other things being equal, one could argue that Al-Gharib could have reasonably foreseen, with the assistance of a lawyer, that a court might apply a mens rea requirement of recklessness for secondary liability for international crimes.6

On the other hand, a recklessness standard for secondary liability has not been applied by international courts and tribunals, while a knowledge requirement has been consistently upheld (Ventura p. 190).7 Various international courts and tribunals have found that the principle of legality can be violated by erroneously applying an incorrect element of a mode of liability. In many cases, these courts and tribunals have spent significant time and energy determining the elements and contours of modes of liability under customary international law in order to uphold the principle of legality (see, e.g., Tadić, ICTY, paras 194-229; Šainović et al., paras 1626-1651; JCE Decision, ECCC, paras 45, 53-88). The customary international law standard of aiding and abetting, the equivalent of German liability for assistance, is, at the very least, knowledge. The knowledge mens rea standard was applicable to the accused at the time his acts occurred under universal jurisdiction, whereas the recklessness standard was not.

The difference between the mens rea requirements of knowledge and recklessness could affect the outcome of a trial and influence a finding of guilt or innocence. Consequently, the Koblenz court erroneously applied a mens rea standard that was lower than the requirement under the applicable customary international law, in a manner that was detrimental to Al-Gharib’s case. The Koblenz court may have violated the principle of legality.

IV. Some final thoughts

In this final part, we make several brief observations related to the use of domestic modes of liability in universal jurisdiction cases.

First, Al-Gharib’s case typifies how international modes of liability are considered by judges in universal jurisdiction cases and, more generally, by domestic lawmakers. Universal jurisdiction is described as jurisdiction based on the nature of crimes. Modes of liability are often an afterthought, not seen as having the same importance as the crimes to which they are linked. While domestic legislators often incorporate international crimes into domestic law, international modes of liability rarely feature in domestic legislation. However, the subject matter of universal jurisdiction, prescribed by international law, extends beyond the crimes. Modes of liability are a central feature of substantive international criminal law, and their definitions work in tandem with those of international crimes to assign accountability. Moreover, modes of liability have developed in international criminal law to apply specifically to international crimes and address situations involving mass criminality. Arguably, international modes of liability are best suited for determining liability in cases involving international crimes. Given their importance, the misapplication of modes of liability when prosecuting international crimes should raise significant legality concerns.

Second, the discussion in this blog has implications for how State Parties to the ICC Statute rely on ICC law in their domestic systems. ICC law does not always reflect customary international law. If an individual is tried under universal jurisdiction for acts that occurred outside of the ICC’s jurisdiction, then ICC law does not apply. If a domestic court arbitrarily applies ICC law, without checking whether this law reflects applicable customary international law, then the court may undermine the principle of legality. For example, in Al-Gharib’s case, the alleged acts occurred outside of the ICC’s jurisdiction. The Koblenz court relied on Section 7(5) of the VStGB which incorporates an ICC definition of torture. However, this definition of torture does not include the customary international law requirement of ‘specific purpose’.8 Consequently, the Koblenz court may have relied on a definition of torture that did not apply to the accused when his acts occurred.

In a similar vein, in the ICC’s recent Ali Kushayb decision which dealt with the Court’s jurisdiction over UN Security Council referrals under Art. 13(b) of the ICC Statute, the Appeals Chamber found that ‘for conduct that takes place on the territory of a state that is not a party to the statute, it is not enough that the crimes charged can be found in the text of the Statute’ (para. 86). The Appeals Chamber held that the Court must uphold the principle of legality while applying the ICC Statute, and thus the Court should consider the laws applicable to the suspect at the time when the conduct occurred. In all likelihood, the Court will need to analyse whether its own law corresponds to the customary international law that was applicable to the accused at the time of his acts to uphold the principle of legality (Dias, pp. 87, 88).

Third, the requirement for domestic courts to identify customary international law is not without challenges. Undoubtedly, the application of an unwritten and often-contentious source of law complicates adherence to the principle of legality and imposes significant burdens on domestic courts. At times, domestic law will offer more certainty or be more specific than customary international law. However, adherence to the principle of legality remedies this issue and protects against uncertainty (nulla poena sine lege certa). Where there is doubt as to the applicable customary international law, the law which favours the accused should apply (in dubio pro reo). At other times, domestic law will be more lenient than customary international law. This will not change the fact that such domestic law was not applicable to the accused at the time their acts occurred. Nonetheless, the retroactive application of more lenient law is less likely to contravene the principle of legality.

To conclude, as we noted in our introduction, universal jurisdiction cases are becoming more and more common. This type of jurisdiction is an important tool in the fight against impunity for international crimes. However, prosecutions in these cases should not undermine an accused’s right to a fair trial. The goals of international justice can only be achieved when trials are fair and adhere to general principles of criminal law. While it may take time for domestic courts to confidently apply international law, the project of universal jurisdiction, and international justice more broadly, will be better for it. 



1 Multi-lateral treaties agreed upon by states (like the ICC Statute and CAT) can establish universal jurisdiction between the signatories for specific crimes. Signatories of treaties accept that certain crimes can be prosecuted in the jurisdiction of any other signatory. A case that involves treaty-based jurisdiction is intra-parties, based on mutual legal agreement, and is not strictly universal. It is perhaps erroneous even to refer to this type of jurisdiction as ‘universal jurisdiction’ given it applies only to the signatories of treaties. References to universal jurisdiction in this blog should be understood as references to ‘pure’ universal jurisdiction.

2 For this blog, we will rely on this understanding of universal jurisdiction over international crimes (see Princeton Principles and the Institute of International Law). There is support for the idea that ‘states have a customary law entitlement to exercise true universal jurisdiction over a narrowly defined list of crimes under international law’ (Kreß, p. 584). Generally, this also seems to be the understanding of universal jurisdiction relied upon by domestic courts adjudicating such cases. However, we recognize that universal jurisdiction is a more complex and contentious concept in scholarship and practice than what we present here (see O’Keefe and Kreß).

3 The dolus eventualis standard is perhaps better described as knowledge that a risk might occur, and the acceptance of that risk. For this blog, we will refer to it as ‘recklessness’.

4 Based on publicly available evidence, it appears that Al-Gharib might have had knowledge of the crimes that occurred. Arguably, the court might have reached the same result if it applied a higher threshold mens rea of knowledge instead of recklessness. Regardless, the misapplication of law still raises important legality concerns. A court should apply the correct law and be able to communicate its reasons for doing so. 

5 If the accused’s conduct was criminalised under Syrian law and German law (double criminality) but not international law, then this conduct should not be prosecuted based on universal jurisdiction. Universal jurisdiction should only be exercised over specific subject matter that is criminalised under international law. If German courts were to apply Syrian law or German law which is comparable to Syrian law, this would be something different to universal jurisdiction. Nonetheless, if the conduct was criminalised under both Syrian domestic law and international law, this could bolster a court’s determination that a criminal conviction for the accused’s conduct was indeed foreseeable and accessible to the accused.

6 Van der Wilt proposes a similarly flexible approach to the principle of legality in universal jurisdiction cases (pp. 257-262).

7 Exceptionally, the SCSL upheld a standard of ‘awareness of a substantial likelihood’ (Brima, SCSL, paras 242 and 243).

8 Notably, the CAT, of which Syria is a signatory, requires the element of ‘specific purpose’.