This paper considers the development of international criminal law and as a feld of study in American criminology. Despite the important U.S. role in establishing the International Military Tribunal and war crimes trials at Nuremberg following World War II, American politicians and criminologists did little to advance the further development of international criminal law or courts. Post-war Cold War tensions between the Soviet Union and the U.S., and domestic research preoccupations of American criminologists, discouraged further contributions. Finally, following the collapse of the Soviet Union and the outbreak of atrocities and war crimes in the Balkans, the United States took renewed interest and helped to create an ad hoc International Tribunal for the Former Yugoslavia [ICTY]. However, when the U.N. established a permanent International Criminal Court [ICC] to handle the prosecution of war crimes, American enthusiasm and support waned, and it ceased during the Trump Administration. Yet there were other signs international criminal law could still be signifcant. When the U.S. was revealed to be torturing detainees in Iraq, and a police detective was found to be operating a torture squad in Chicago, the U.N. High Commission on Human Rights [UNHCHR] used its procedures to pressure the U.S. and the city of Chicago to investigate. Later, the same procedures were used to pressure Chicago to support a reparations program for victims and families of police torture. International criminal law was more resilient and relevant than is commonly believed.