This chapter examines the issue of shared complicity in atrocities perpetrated by the Japanese military in the Asia-Pacific region between 1941 and 1945. Atrocities in war are often presented as a relatively simple morality tale in which good and evil are obvious, and in which perpetrators should be pursued in the interests of justice for victims. Cases from the Asia-Pacific region during the Second World War suggest a more complex reality, including instances relating to prisoners in captivity. Camps in which the Japanese military held Allied prisoners of war are notorious for brutality and privation. While Japanese military personnel committed many crimes in camps, they were sometimes aided by Allied inmates, especially senior officers seeking to control their own subordinates, in actions that would later be considered as war crimes. Evidence of cooperation between captors and captives, however, was routinely suppressed in post-war trials and expunged from the publicly acknowledged collective memory of former prisoners. Examples of prisoners’ complicity in Japanese actions that were later classed as war crimes blur the usual understanding of what constituted mistreatment of prisoners and when it might have been justified.