The Kenova report sheds welcome and forensic light, long overdue, on how British security forces repeatedly permitted, and probably directed, illegal killings by their agents in Northern Ireland. Its most damning finding is that “murders committed by [British] agents” include “cases in which it was arguable that they were acting on behalf of the state”. It is no surprise to anyone familiar with the Northern Irish conflict that the British state used illegal violence, both against republican terrorists and uninvolved civilians. But it still comes as a shock to see it so baldly demonstrated, in such detail, in an official...