Having identified the differences between the concept of legality and the much more complex concept of legitimacy, the author scrutinizes the legality and the legitimacy of the existing international criminal tribunals. Their legality has been put in doubt only concerning the International Criminal Tribunal for the former Yugoslavia (ICTY) and the Special Tribunal for Lebanon (STL), but the criticisms have been or could be overcome. Assessing the legitimacy of these tribunals is instead a more difficult task. In fact, misgivings have been voiced essentially concerning the legitimacy of the ICTY and the STL, but not the International Criminal Court (ICC) and the other international criminal courts. The legitimacy of the STL in particular deserves to be discussed: even assuming that the STL initially lacked some forms of legitimacy, it could achieve it – or confirm it – through its ‘performance legitimacy’. The author then suggests what the realistic prospects for international criminal justice are. Convinced as he is that it is destined to flourish even more, he tries to identify the paths it is likely to take in future years.

The essay argues that the absence of an international treaty definition of aggression in international law should not preclude the prosecution of its perpetrators. Two legal regimes of responsibility, namely the prohibition against aggression as an international wrongful act and the crime of aggression have been entangled. Once one separates the criminal liability of individuals from state responsibility, a definition of the crime of aggression can be seen. According to the author, the contours of such a new definition contain the requisite degree of certainty for judicial approaches instead of merely political approaches. Consideration is also given as to whether conspiracy to wage a war of aggression may also be regarded as a separate crime within international criminal law.

The International Criminal Tribunal for the former Yugoslavia (“the International Tribunal”) was established over four years ago in response to the mass killings, widespread and systematic rape and “ethnic cleansing” being practised in the former Yugoslavia on a scale and of a ferocity not seen on the European continent since the end of the Second World War. The United Nations Security Council considered that this situation constituted a threat to international peace and security. It therefore established the International Tribunal as a subsidiary judicial organ, in the belief that this would help halt and redress such violations.

El Tribunal Penal Intemacional para ex Yugoslavia (en adelante, «Tribunal Internacional») fue instituido hace más de cuatro años como respuesta a las masivas matanzas, las violaciones generalizadas y sistemáticas y la «depuración étnica» que se estaban cometiendo en ex Yugoslavia, con una dimensión y un salvajismo sin precedentes en Europa tras la Segunda Guerra Mundial. El Consejo de Seguridad de las Naciones Unidas, considerando que esta situación era una amenaza para la paz y la seguridad internacionales, decidió instituir el Tribunal Intemacional como órgano judicial subsidiario, con la convicción de que ello contribuiría al cese de tales prácticas.

A review of the current state of legal regulation in the field of human rights is likely to give the disappointing impression that international legislation is unequal to the task of checking widespread disregard for human dignity. Despite the vast proliferation of instruments setting standards on human rights, imposing obligations as regards the observance of those standards and establishing procedures to deal with breaches of those obligations, violations of human rights continue, their perpetrators apparently undeterred.