“the solemn renunciation of war as an instrument of national policy necessarily involves the proposition that such a war is illegal in international law; and that those who plan and wage such a war, with its inevitable and terrible consequences, are committing a crime in so doing.”
Nuremburg War Crimes Tribunal
International Law
The General Treaty for the Renunciation of War [Kellogg-Briand Pact]
The United Nations Charter
The Nuremburg Judgement
The Nuremburg Principles
The Rome Statute of the International Criminal Court
Domestic UK Law
The International Criminal Court Act 2001