Atrocity fabrication – the invention and reporting of atrocities committed by an adversary without knowledge that they ever occurred – has a centuries-long history at the heart of propaganda and power politics as an effective means of moving public and international opinion. Its use can provide pretext for a range of hostile measures against its targets, transforming in the public eye wars of unprovoked aggression into wars of liberation of the oppressed, or turning blockades to starve enemy civilians into humane efforts to pressure abusive governments under the moralistic label of sanctions. As it plays a large and growing role in global conflict in the 21st century understanding atrocity fabrication and the consistent means by and ends to which it has been used has become crucial to comprehending geopolitical events in the present day.