The famous first line of the Nuremberg Code, written by the judges at the Nazi Doctors’ Trial in 1947, is that “The voluntary consent of the human subject is absolutely essential”. The Code is usually noted for the phrase “voluntary consent”, a condition for human experiments that the judges considered to be “absolutely essential”. But the latter imperative phrase has elicited far less commentary: Essential for what and for whom? I argue that the field known as bioethics, the study and implementation of moral values and human rights in medicine and the life sciences, is a creature of what political scientists call the post-World War II liberal international order (LIO), or simply the rules-based order. The Doctors’ Trial was a key element in the Allies’ attempt to bring medical science within the rubric of the rules-based order. The current threats to that order, from the after-effects of the pandemic to the war in Ukraine to the results of climate change, present important implications for the core values of bioethics as a creature of the postwar international order.