In 2012, James Stewart published an article in this journal. The piece – ‘The End of “Modes of Liability” for International Crimes’ – argued for the abolition of accomplice liability in international criminal law and the adoption of a unitary model of participation in crime. This article argues that Stewart's proposal is flawed. As a matter of moral responsibility, the distinction between principals and accomplices follows from the recognition of individuals as moral agents. Turning to ordinary criminal responsibility, neither practical benefits nor expressive benefits nor the mitigating effects of the distinctive institution of criminal sentencing justifies the abolition of the distinction between principals and accomplices. Moreover, despite the collective nature of many international crimes, international criminal law ought to strive to accurately differentiate, in the attribution of responsibility, among participants. Only a differentiated model of participation can accurately and defensibly capture the different ways that individuals contribute to wrongdoing.