Crime of aggression is a concept within international criminal law and political science that investigates the unlawful use of armed force by a state against the sovereignty, territorial integrity, or political independence of another state, focusing particularly on the individual criminal responsibility of leaders who plan, initiate, or execute such acts. This academic concept examines the definition, elements, and historical application of this crime, as codified in international instruments like the Rome Statute of the International Criminal Court, analyzing its significance for international peace, security, and the development of international accountability mechanisms for state-level conduct involving armed conflict.