On its seventy-fifth anniversary last year, the Nuremberg war crime trials moved again into the spotlight of public attention. To the present day, Nuremberg is mainly portrayed as the birth of international criminal law being the first tribunal that held individuals accountable for war crimes committed during the Second World War. As we argue in this article, there is an often-overseen dark legacy of Nuremberg as it represents an unused opportunity to establish accountability for inhumane military practices, especially in air warfare, being of tragic influence for the postwar development of International Humanitarian Law (IHL) as a whole. Going beyond the existing criticism already voiced on Nuremberg’s shortcomings, we hold that the Tribunal’s reluctance to prosecute bombing practices sowed the seeds for the decay of IHL by creating institutionalized silences, especially for massive violations of the principle of distinction. The tribunal thereby sidelined pre-war IHL and infected the development of post-war IHL by retroactively legitimating the bombing practices of the Axis powers and at least indirectly of the Allies. We argue that the failure to prosecute ‘total war’-practices and reestablish former restrictive legal structures regarding aerial bombardment has fundamentally eroded the pre-war meaning of the principle of distinction leading to its downfall in the First Additional Protocol to the Geneva Convention of 1977. We describe these developments as a form of judicial desuetudo, meaning the abrogation of a rule through its subsequent non-enforcement by an international court during and after massive law violations because of perceived or real political constraints.