enforcement, or indeed insisted on doing so.34 The patina of international legality conferred each time has, we might say, simply transformed the pirates into privateers. The paradigm for this, as Richard Falk has argued,35 can be found in the Gulf War of 1991, and the same has occurred in Somalia, Rwanda, and Haiti, and in the war of Bosnia-Herzegovina (1991–95) as well as, a posteriori, in the war over Kosovo (1999). In all these cases, as Gaetano Arangio-Ruiz has emphasized, any nation which declared itself ready and willing to do so was authorized to use its military forces, under its own command, while on the part of the Security Council there has been ‘no effective direct exercise of military coercion’.36 In reality, the Security Council has renounced its primary function—the control and limitation of the use of international force—and shown itself ready not only to authorize the use of force beyond the provisions of the Charter, but also to legitimize ex post facto the military conduct of the major powers, including the use of quasi-nuclear weapons of mass destruction such as ‘fuelair explosives’ and the murderous daisy-cutter bombs, quite apart from countenancing the extermination of innocent civilians.
On top of all this, in the UN Charter we find no definition of the notion of a ‘war of aggression’, and this, at least in theoretical terms, makes the Security Council the unchallengeable arbiter in resorting to or renouncing the use of force against aggressor states that violate or threaten to violate world peace. There is no reference to such a definition even in Article 51, which authorizes a state that has come under attack by another state to resist with the use of force until such time as the Security Council shall intervene. From the text of the Article one can merely deduce that the aggression must consist in an ‘armed attack’, not simply a threat of attack, and this should at least rule out the idea—resolutely defended by the United States and Israel—of the legitimacy of ‘preventive or pre-emptive self-defence’.37 In reality, the lack of a precise notion of ‘war of aggression’, as the voluminous literature devoted to interpreting Article 51 and the innumerable theoretical and practical controversies which have resulted go to show, has rendered this Article a favourite tool in the hands of the major powers to justify their wars, in the name of an ever more elastic notion of ‘self-defence’.38
Very belatedly, in December 1974, the UN General Assembly attempted to fill this normative vacuum by issuing Resolution 3314 (XXIX), giving an elaborate definition of ‘aggression’. Aggression is referred to in the preamble as ‘the most serious and dangerous form of the illegal use of force’,39 while Article 1 describes it in lapidary fashion as ‘the use of armed force by a State against the sovereignty, territorial integrity or political independence of another State’.40 Article 3 gives a wide-ranging analytical specification of possible modes of aggression.41 However, an important caveat is introduced in Article 2, where it is specified that aggression is not to be automatically imputed to the state that is the first to use military force against another state. The Security Council, taking into account the circumstances, and whether the consequences of the attack are of sufficient gravity, may decide that the first to use force is not in fact guilty of the crime of aggression.42
As has been observed, this definition—produced by the General Assembly and not the Security Council, and hence not mandatory—is incomplete, and was always intended to be so.43 Article 4 actually states that it is not to be regarded as exhaustive, since the crime of aggression can be combined with other alleged transgressions in war at the discretion of the Security Council.44 Moreover—and this is a particularly grave omission—the resolution does not contemplate any sanction against those committing a crime of aggression. Article 5 limits itself to two utterly banal considerations in the wake of the sentence pronounced by the Nuremberg Tribunal, namely that ‘a war of aggression is a crime against international peace’ and that it incurs ‘international responsibility’.45
Antonio Cassese has argued that, in this and other cases, one can see the tendency of the major powers to ensure that the notions of ‘act of aggression’ and ‘war of aggression’ should not be clearly defined, thereby making it impossible to enforce the provision laid down in Article 2, section 4 of the UN Charter forbidding nations to use force. In his view, this tendency prevailed because the major powers,
when it comes to actively applying this measure, aim to keep a large degree of freedom of action both at the individual level, and collectively through the United Nations Security Council. The definition of ‘aggression’ has been left in a sort of limbo with respect to its characterization both as a state crime and as an international crime imputable to individuals.46
More generally, Giorgio Gaja has pointed out the existence of an ‘evident paradox’: while the prohibition of the use of force is a fundamental principle of international law, and violation of this principle is considered one of the most serious examples of ‘international crime’, it is practically unknown for one state to ask for sanctions to be imposed on another state or its citizens on the basis of an accusation of aggression.47 The criminalization of aggressive war has thus failed to produce any significant developments—not in normative terms, not in the structure of the international legal system, and still less in dissuading nations from having recourse to the arbitrary use of force.
War as a crime for which individuals are indictable
The new concept of war that gained ground in the first decades of the twentieth century did not just postulate a war of aggression as an international crime imputable to states: it also introduced, as we have seen, the possibility of individuals being indicted for this and other international crimes. And this has played a fundamental role in moulding international criminal justice.
Up to the end of the Second World War, international institutions had never prosecuted individuals in law. Indeed, from the dawn of modern international law and its founding fathers Hugo Grotius, Alberico Gentili and Baltasar Ayala, internationalist doctrine had excluded the possibility of individuals being considered subjects in the international legal order, whether in conjunction with, or in place of, the nation-states. International courts of justice had never been invested with obligatory jurisdiction, and had in fact been confined to relatively marginal issues. To maintain a world order, the major powers had had recourse to political and military force, treaties and diplomacy, rather than to legal instruments. This was the case, in particular, for the Holy Alliance, the League of Nations and the United Nations.
From the first decades of the twentieth century, commentators in the West began to argue the case for extending the judicial function to the international arena. As we have noted—and as Carl Schmitt insisted—the dress rehearsal for this radical doctrinal departure was the incrimination of Kaiser Wilhelm II of Hohenzollern as a war criminal at the end of the First World War. In its indictment of the venerable emperor, Article 227 of the Versailles Treaty accused him of ‘supreme offence against international morality and the sanctity of treaties’, a formula dictated by Wilson.48 This accusation, with its rhetorical and scrupulously non-legal language, did not refer to the traditional notion of ‘war crimes’, involving violation of the so-called jus in bello. Such a violation concerned the conduct of belligerents that infringed the norms of the ‘law of warfare’, meaning the proper conduct of war on land or at sea, the rights of prisoners, and so on.
Having achieved victory in the First World War, the Entente allies were determined to criminalize and punish warfare as such—specifically as an act or series of acts of aggression—and insisted that individuals, cited by name, be held responsible for this crime.49 Article 227 required that the kaiser should stand trial, together with high-level German political and military figures, before an international court composed of judges representing the five victorious powers (Britain, France, Italy, Japan and the United States). Furthermore, other articles in the Treaty required Germany—although no such obligation was to be found anywhere in either international treaties or customary law—to hand over some 900 named individuals accused of violating laws and war customs, so that they too could be tried.50
As
