Jurisdiction — Universal — Crimes against international law — War crimes — Crimes against humanity — Canadian legislation extending jurisdiction of Canadian courts to war crimes and crimes against humanity committed outside Canada during World War Two — Whether permissible in international law — Whether constituting retroactive criminal legislation — Extraterritorial — Presumption against extraterritorial effects of criminal legislation — Whether Canadian Parliament possessing authority to pass legislation having extraterritorial effects

War and armed conflict — War crimes and crimes against humanity — Whether principle of individual criminal responsibility for war crimes and crimes against humanity already established during World War Two — Hague Convention No IV respecting the Laws and Customs of War on Land, 1907 — Charter of the International Military Tribunal

Human rights — Criminal penalty — Retroactive criminal legislation — Prohibition of retroactive criminal legislation — Canadian legislation extending jurisdiction of Canadian courts to war crimes and crimes against humanity committed during World War Two — Whether contrary to principle that criminal legislation should not be retroactive

Treaties — Application — Hague Convention No IV respecting the Laws and Customs of War on Land, 1907 — General participation clause — Application of Convention during World War Two

Relationship of international law and municipal law — Treaties — Application in Canadian law — Hague Convention No IV respecting the Laws and Customs of War on Land, 1907 — The law of Canada