Contrary to what many people think, the trials at Nuremberg did not primarily concern the prosecution of Nazi leaders for perpetrating the Holocaust as a genocide or crime against humanity, or even for various war crimes, such as the fire bombing of Coventry. Rather, the primary purpose of the Nuremberg trials was to prosecute Nazi leaders for crimes against peace and waging aggressive war. As the International Military Tribunal noted, aggression “is not only an international crime; it is the supreme international crime.” The Nazi leaders who were executed at Nuremberg were convicted primarily of crimes against peace, eight of them convicted for “participation in a common plan or conspiracy” to wage aggressive war. Today, however, while the International Criminal Court lists the crime of aggression as falling under its jurisdiction, there can be no prosecutions for this crime today because there has been no agreement about what it means to wage aggressive war and what are the elements of this crime.

The main question taken up in this chapter is when, if ever, it makes sense to hold individuals criminally liable for starting or perpetuating an aggressive war in terms of their mental states. While it seems to have made sense to hold Nazi leaders responsible for the Holocaust, did it also make sense to hold individuals criminally liable for invading Poland, for example? What would link their individual intentions to the collective intentions of the State?