The International legal system (ILS), is no longer in its infancy and is in the midst of expansive development. The ‘proliferation’ of the ILS has been a topic of discussion for many legal scholars over the past half-century, with many fearing a ‘fragmented’1 as opposed to a ‘unitary’ legal system. Following the end of World War II, the Charter of the United Nations founded in 1945, established the International Court of Justice (ICJ) (the successor of the Permanent court of International Justice (PCIJ)) as the principal judiciary body of the UN under Art 92.2 Throughout this period the ILS was immature, and for a substantial period required International courts and tribunals with broad jurisdiction. This situation improved throughout the 1990s during the post-Cold War period, followed by the establishment of the three tribunals, for Yugoslavia (ICTY) (1993), Rwanda (ICTR) (1994), and the Law of the Sea (ITLOS) (1996). This progression was then followed by the establishment of highly specialised dispute settlement bodies such as the International Criminal Court (ICC), the Dispute Settlement panels of the World Trade Organisation (WTO), Dispute Settlement Panels of the North American Free Trade Association (NAFTA), and various investment tribunals acting under the International Centre for Settlement of Investment Disputes (ICSID). Consequently, the proliferation of the ILS has not permitted the ICJ to act alone as the principal judiciary of the UN, as it has always coexisted with third-party dispute settlement bodies. The proliferation of the ILS has seen IL which was once governed by ‘general international law’, now become a field of operation for specialist systems such as ‘human rights law’, ‘international humanitarian law’, ‘law of the sea’, etc. each possessing their own principles and institutions. 3
The end of World War II not only seen the proliferation of International legal bodies, but as to did the subjects governed by International law (IL). Originally states as defined under Art 1 Montevideo Convention on the Rights and Duties of States (MCRDS),4 were the sole subjects of IL. Following the Reparation for Injuries case5, the ICJ established the capacity for International Organisations (IO) to claim under International law. Today, Private Individuals, multinational corporations, intergovernmental and non-governmental organisation are now universally acknowledged as possessing International legal personality and in turn, imposing rights and obligations onto such International subjects.
Consequently, as a heterogeneous legal system, legal scholars have questioned the ILS as a unitary system in light of the so called ‘fragmentation’ and ‘proliferation’ of international law. As the former president of the ICJ Judge Gilbert Guillaume suggested, the proliferation of the ILS “gives rise to a serious risk of conflicting jurisprudence”, also stating “the proliferation of International courts may jeopardize the unity of international law”.6 On the other side of the spectrum lies those who have supported the ILS despite its decentralised nature, including Judge Greenwood in the Dialllo case7, and J. Charney8, who both agree the coherence of the ILS does not appear to be threatened by the proliferation of IL, as such IC and tribunals draw jurisprudence from one another. Such practice translates into stare decisis rule found in Common Law systems; however, under the ILS there is no such doctrine, as exemplified under Art 59 of the ICJ statute, ‘the decision of the court has no binding force except between the parties and in respect of that particular case’.9However, the ICJ is authorised under Art 38 of its statute, to apply judicial decisions as a ‘subsidiary means for the determination of rules of law”. 10 While there is no doctrine of stare decisis, the ICJ frequently cites its own (or PCIJ’s) previous decisions as ‘precedents’.11 The ICTY also formulated a principle of judicial precedent in Prosecutor v Žlatko Aleksovski.