(Ця стаття також доступна українською мовою тут.)

Recent events in Ukraine have rekindled the interest to prosecute state leaders for the crime of aggression. Even though the Rome Statute has a provision on the crime (Article 8bis), due to particular limitations written into the treaty, the International Criminal Court (ICC) is unable to prosecute anyone allegedly involved in the commission of the crime of aggression on the territory of Ukraine. For that reason, movement is afoot to launch national investigations of aggression, set up a special tribunal with UN General Assembly support, or assemble Ukraine and a group of other states establish a special tribunal. On the latter option, a group of law professors and distinguished public figures issued a statement proposing “the creation of a special tribunal with a limited focus on the crime of aggression.”

The group further suggests that jurisdiction should cover “both the perpetrators of the crime of aggression and those who materially contributed to or shaped the commission of that crime” without any express limitations to state leaders. This raises the question of who is to be blamed for the crime of aggression since “contribution” is a fluid concept that may stretch criminal liability to a breaking point — allowing for an excessive sweep of people across the state apparatus (and beyond) to be blamed for aggression. As the Nuremberg Military Tribunal (NMT) held, there has to be a standard for criminal responsibility, a threshold of sorts, that draws a line between the guilty and the innocent for wars of aggression and that prevents collective guilt and mass punishment (p.1126). That line drawing includes having a limiting principle so that the scope of criminal liability for aggression does not even begin to approach the foot soldiers.

The so-called leadership clause is an integral part of the definition of the crime of aggression in the Rome Statute. Article 8bis(1) limits criminal responsibility to “a person in a position effectively to exercise control over or to direct the political or military action of a State.” There are states such as Germany (Section 80), Poland (Art.117), Ukraine (Art.437), and others that do not explicitly include the element of leadership in their penal codes. That notwithstanding, as will be shown in the remainder of this article, the leadership clause is part of customary international law and as such implicit in the actus reus of the crime of aggression.

From the outset, the crime of aggression was considered a leadership crime—a crime of leaders who devise state policies which excludes followers, among others, from criminal liability. It was prosecuted for the first time at the Nuremberg International Military Tribunal (IMT). Although there were no provisions on leadership in the Nuremberg Charter, a high-level position in the Nazi Party, government, or military was one of the key requisites in determining a defendant’s responsibility during the trial. Justice Robert H. Jackson, Chief Prosecutor for the United States in the Nuremberg trial, stated in his opening speech that the intention of the prosecution is not to incriminate the entire German people, but “to reach the planners and designers, the inciters and leaders without whose evil architecture the world would not have been for so scourged with the violence and lawlessness…of this terrible war.” Later he made it clear that during the London conference (where the Nuremberg Charter was adopted), the drafters’ intention was to exclude the followers from responsibility for aggression and focus on the most senior leaders: “It never occurred to me, and I am sure it occurred to no one else at the conference table, to speak of anyone as ‘waging’ a war [of aggression] except topmost leaders who had some degree of control over its precipitation and policy” (p.198).

A couple of months after the IMT rendered its judgment, the Allied Powers issued Control Council Law No. 10 authorizing the occupying authority in each of the zones of occupation to establish tribunals to prosecute war criminals and other similar offenders not addressed in the IMT judgment. In IG Farben, the chambers reiterated the IMT’s approach that a government and its military power are led by individuals who control the policies that may lead to aggressive war and that the responsibility of such individuals is the subject of the crime of aggression (p.1125). This was the case brought by the United States against 24 members of the board of directors of the largest industrial corporation in Europe at the time, IG Farben. In his concurring opinion, Judge Herbert stressed the great importance of IG Farben corporation to the war effort and maintained that it provided critical materials without which the policy makers of the Third Reich would not have considered commencing aggressive war. Judge Herbert held that the defendants (industrial leaders) “acting through the corporate instrumentality, furnished Hitler with substantial financial support…[and] carried out activities indispensable to creating and equipping the Nazi war machine” (p.1297). The tribunal stated to avoid “the possibility of mass punishments” the crime of aggression must be limited to “only major war criminals-that is, those persons in the political, military, and industrial fields, for example, who were responsible for the formulation and execution of policies” (pp. 1124-25). All defendants were eventually acquitted on charges of crimes against peace, as the court was not satisfied with the evidence on the mens rea requirement (p.1123).

Later in High Command (where 14 high-ranking officers in the German military were prosecuted for aggression), the NMT held that the accused’s occupation of a position to shape or influence the policy was an intrinsic element of the crime, without which one could not be held responsible (p.487):

There first must be actual knowledge that an aggressive war is intended and that if launched it will be an aggressive war. But mere knowledge is not sufficient to make participation even by high ranking military officers in the war criminal. It requires in addition that the possessor of such knowledge, after he acquires it shall be in a position to shape or influence the policy that brings about its initiation or its continuance after initiation, either by furthering, or by hindering or preventing it. If he then does the former, he becomes criminally responsible; if he does the latter to the extent of his ability, then his action shows the lack of criminal intent with respect to such policy.

The “shape or influence” clause became the first explicit leadership requirement for the crime of aggression.

At the ICC, the crime of aggression has been within its purview ever since 1998 and the adoption of the Rome Statute. Nonetheless, in contrast to the three other core crimes (genocide, crimes against humanity and war crimes), there was no agreement upon its definition, which was left to the future review conference (Art.5(2)). The leadership nature of the crime, however, was undisputed. In the negotiations preceding the adoption of the Rome Statute, the German delegation in a proposal on February 1997 (reprinted here) suggested the replacement of the old “shape or influence” by the “control or direct” clause,  as a more appropriate wording to capture modern state dynamics. “Control or direct” thus remained in the definition until the adoption at the Kampala Review Conference 2010. The limited scope of the new leadership clause was criticized during the negotiation proceedings, but the leadership nature of the crime of aggression has never been contested.

There is a clear understanding that the crime of aggression is “reserved” for prosecuting leaders who formulate or execute state policy and despite some states’ reluctance to include the leadership element in their domestic legislations explicitly, any future prosecutions have to take the leadership requirement into consideration in line with customary international law. Otherwise, they run into the risk of over-criminalization and their proceedings may not gain legitimacy within the broader international community.