Fragmentation of the notion of co-perpetration in international criminal law?

The modes of liability that regulate participation in the context of international crimes tend to be structured in a way that takes into account the particular modalities and forms that connote the commission of war crimes, crimes against humanity and genocide. Moreover, mechanisms that extend the scope of individual criminal responsibility beyond one’s own actions are not unusual in international criminal law (i.e the command responsibility doctrine). Attention must be paid that the principle of individual and culpable responsibility is not violated, since from the Nuremberg process on it has been recognized in international criminal law exactly as in domestic law as a fundamental principle that refuses collective forms of criminal responsibility as well as strict liability for international crimes. In the international macro-criminal context specific problems arise in the process of attributing criminal responsibilities to individuals involved in the joint commission of crimes, where a plurality of persons acts with a common plan. Such difficulties consist in particular in distinguishing between (co-)perpetration (as a form of principal liability) and mere participation (as a form of secondary liability) to the common plan.