Customary Method in International Justice. As developed in this dissertation, international justice comprises a set of sources of law that might be invoked so as to secure accountability for acts of atrocities, including international criminal law and international human rights law. In contrast to the inductive method of custom identification (which seeks empirical evidence of both State practice and opinio juris), some writers argue that norms in these areas of law are more amenable to deductive forms of reasoning that emphasise statements over actions.557 If international justice is more open to the development of custom from deduction, then this would make these fields of law particularly fertile terrain from which an Assembly resolution (and indeed other documentary sources) could take root. In this respect, the areas of law relating to international justice have been noted to support a less stringent burden of proving custom, on the basis that they are underpinned by elementary considerations of morality or, as the ICTY Trial Chamber observed in Kupreškić, ‘the demands of humanity or the dictates of public conscience’.558 The Martens Clause has also been invoked to support greater latitude in custom finding, in permitting decision-makers to fill gaps where State practice conforming with opinio juris is absent.559 During debate on the appropriate method for regulating outer space, the US delegate also noted that an Assembly resolution, rather than a treaty, was sufficient given that its subject matter concerned ‘shared humanitarian and scientific concerns of the international community’, such that ‘States would willingly comply with such a resolution’.560 This willingness to dispense with State practice reflects, as Xxxxxx noted, a sliding methodological scale in custom-finding: the more destabilising or morally distasteful the activity, the more readily decision-makers will substitute one element for the other; conversely, where the activity is not so destructive of widely accepted human values, the more that the decision-maker is to be exacting in looking to both elements of custom.561 The CIL Conclusions seem to offer mixed support for methodological variances in the identifications of customary international law. On the one hand, the two-element approach (i.e. State practice and opinio juris) are ‘essential conditions’ and apply in ‘all’ fields of 556 UNGA Sixth Committee, First session, 22nd meeting (22 November 1946) UN Doc A/C.6/84, 102. 557 Xxxxxx Xxxxxxx, ‘Traditional and Modern Approa...
