The crime of aggression was neither capable of being a "crime" within the meaning of the Criminal Law Act 1967 s.3 nor an "offence" within the Criminal Justice and Public Order Act 1994 s.68(2). Therefore, individuals facing charges for criminal damage and aggravated trespass arising out of their actions in protesting against the war in Iraq could not argue that they were using reasonable force to prevent the commission of a crime, nor that the activities of the Crown at the military bases were unlawful.

[2006] UKHL 16