Aiding and Abetting

Aiding and abetting as a mode of liability in international criminal law generally refers to acts or omissions that assist, encourage or lend moral support to a crime and substantially contribute to its commission (actus reus). Further, a person must act, or omit to act, with the knowledge that he or she assists, encourages or lends moral support to the crime (mens rea). While aiding and abetting has been applied to numerous factual scenarios over the years, it has, of late, been the source of significant controversy in international criminal law. As a result, it is perhaps one of the most scrutinised and debated modes of liability in recent times. After distinguishing aiding and abetting from other modes of liability, discussing its scope of application and its generally accepted elements, this chapter identifies and analyses 11 issues that have emerged from the case law of the ad hoc and hybrid international criminal tribunals and from the International Criminal Court (ICC): (i) specific direction and the actus reus; (ii) the definition of the substantial contribution/effect actus reus element; (iii) the actus reus threshold at the ICC; (iv) purposive mens rea at the ICC; (v) knowledge vs. purpose and the mens rea; (vi) recklessness and the mens rea; (vii) the commission of a crime at the ICC; (viii) pior agreement and ex post facto aiding and abetting; (ix) criminal law duty to act and aiding and abetting by omission; (x) complicity in genocide vs. aiding and abetting genocide; and (xi) encouragement or moral support and the principal perpetrators. An overall assessment of aiding and abetting, its status under international criminal law, evidentiary factors and conclusive principles follow.