My dissertation focused on how we should change our perception of the public international legal system. It has been presupposed by the majority of international lawyers that international law is hierarchy based, where certain legal rules automatically have priority of application over others. Jus cogens norms are seen to represent legal rules containing the highest moral standards, thereby having the greatest importance and priority. I considered the functions that this seemingly foundational concept provides in practice. I split the consideration of ‘function’ as both theoretical and directly practical, or substantive, where the jus cogens status of a legal rule contributed directly to its application over conflicting legal rules.
I firstly argued that jus cogens provided a valid theoretical function. It strives towards providing a minimum standard of morality for law to abide by. The system of international law contains no formal regulatory process and is inherently flexible. It enables state actors (ie government officials) to operate a cost/benefit analysis on determining whether to breach international law rules. Consequently, this theoretical function of jus cogens provides a comfort measure, as it shows the system’s interest in preserving a particular set of moral standards. Such a function is necessary when considering the consistent levels of debate that arise over whether state actors are acting illegally and have accountability, not least in the context of contemporary international conflicts like the Syrian civil war.
I found that from a substantive perspective, the jus cogens concept had little impact on the judiciary’s application of legal rules in cases. I considered the legal areas that still have relevance in applying jus cogens today, for example the death penalty for juvenile offenders (aged under 18), and whether state immunity could be revoked based on human rights grounds. I argued that non-legal, often contextually political and moral factors relating to the cases that mentioned jus cogens had practically influenced the application of legal rules. The jus cogens ‘label’ affixed to certain rules provided no practical influence to legal application and references to it instead served as conforming to a formality or expectation within the legal system. I explained that this was not the fault of the international or domestic courts who, in judgments, have been reluctant to tackle the jus cogens concept. Instead, it was due to the inherent difficulties that arise when attempting to define how to determine whether a legal rule has jus cogens status. Discourse has tried to address this issue of characterisation for decades but without much progress. However, what remains clear is a defined structure towards characterising the parameters of jus cogens. This involves adopting a theoretical approach followed by explaining how it can be applied by considering a suitable methodology. I found underlying flaws with this characterisation process. The flaws stemmed from the initial step that relies on adopting either a positivist or naturalist conception of approaching international law. In jurisprudence (legal theory), positivists focus on amorally describing what law is, whereas naturalist lawyers focus on describing what law is with a moral conception. Whilst these two traditions of thought remain highly debatable in the field of jurisprudence as a whole, in the context of international law, they both appeared completely unworkable in practice. Instead, I posited another way to consider more pragmatically the jus cogens concept and, more broadly, how the international legal system should be perceived.
In the final part of my dissertation, I asserted that the inherently theoretical nature of jus cogens means that it should not be treated as a concept containing substantive value. It is instead a concept that has been used for the benefit of international lawyers in their creation of intellectual arguments. The concept came about as it seemed to solve a foundational, theoretical problem with international law. This problem relates to arguments involving constitutionalism, which highlights the divide between limitations in the domestic constitutions of states and the international legal system. As a flexible system, legal rules are formed based on state actors consenting to them. This can be done through custom or by the signing of treaties. States can also persistently object to a particular rule in order to avoid being bound by it. The jus cogens concept was seen to override the ability of states to persistently object. This was arguably conveyed in the Domingues case which involved a man being tried for crimes he committed when aged sixteen. The US government tried, but failed, to use the persistent objector status against adopting the international law norm of prohibiting the death penalty for juvenile offenders, as it was considered to be morally impactful enough to form jus cogens. However, even with this case, defining what laws actually constitute jus cogens status remains unclear thereby allowing other factors to influence judicial decision-making.
The lacking practical influence that the jus cogens concept brings means that it cannot form a source of constitutionalism, thereby emphasising that the concept needs to be reconsidered in light of the international legal system. Discourse should therefore not attempt to codify moral influences relating to legal rules and their application and should instead focus on the non-legal, often political and moral factors that influence legal application in a dynamic international society. The inherent flexibility of the legal system enables this to happen. Concepts like jus cogens function to provide a theoretical comfort measure on how international law is perceived to preserve certain moral standards, and it can be seen as a tool to encourage states to abide by a minimum standard of behaviour. It should, however, be widely recognised for its theoretical focus, namely in critiquing, rather than explaining, how international law functions and is applied.