Customary International Law: A Third World Approach

Cambridge International Law Journal

7 July 2020

International law (“IL”) does not contain a structure of legislation like that of national legal orders, as it is decentralized and lacks a supreme authority.

International law (“IL”) does not contain a structure of legislation like that of national legal orders, as it is decentralized and lacks a supreme authority. This raises the question of what rules govern the law-making process within the body of IL. The question is twofold – firstly, what the content of these rules is, and secondly, what their content ought to be. The normative part of the question requires a standard of criticism, based on which it can be answered. This post adopts the framework of the Third World Approaches to International Law (“TWAIL”) to do this.

Article 38(1) of the Statute of the International Court of Justice enumerates the sources of international law the Court shall use. Customary international law (“CIL”) is one such means. This article, using the framework of TWAIL, exposes the shortcomings of the traditional approach to determining CIL which relies purely on an analytical, formal basis, without delving into the historically contingent influences leading to its formation. Further, the article provides for a process of formation of CIL that could preclude these shortcomings.

While TWAIL’s general claim posits that IL prescribes rules that intentionally disregard the uneven development (of the Third World (“TW”)) in favour of universal global standards, this post argues that second-order rules (rules governing the law-making process), such as those dealing with the formation and determination of CIL, lead to this result. This is substantiated by a critique of the doctrine of uti possidetis, which is considered CIL.

This post critiques the procedural legitimacy of CIL on two grounds – first, that the practice of TW states is generally not considered; and second, that the formation of CIL relies solely on the coordination of states, with no deliberative reasoning, leaving very little avenue to critique its substantive content.

Does CIL adequately account for the practice of TW states?

There exists a lack of availability of TW state practice. One of the primary reasons for this is that newly independent states are bound by rules of CIL that preceded their existence, in the formation of which they had no role to play. Further, cultural factors, such as the fact that the practice of active documentation (as evidence of CIL) is more prevalent in the West, indicates a heavy Western bias.

The doctrine of uti possidetis exemplifies the aforementioned shortcomings. As per this principle, newly independent states must inherit the borders that existed at the time of their independence, generally drawn by the colonizers for administrative purposes. This doctrine forms the basis of Art. 11 of the Vienna Convention on Succession of States in Respect of Treaties, 1978 (“VCSST”). It is premised on the rule of CIL requiring all administrative borders to be converted to international borders, for reasons of stability, efficiency and convenience. Its acceptance as customary law is evidenced by state practice during the decolonization of Latin America, Africa and Asia. Further, the ICJ and the Badinter Commission termed it a ‘general principle’ and a ‘rule of general scope’.

The effect of the lack of involvement of TW states in the creation and acceptance of rules as CIL is especially augmented for this rule, as it is most relevant specifically to such (newly independent) states. Further, scholars have claimed that, consequentially, the universal application of this principle has been harmful for regions that, prior to colonization, had a culturally different notion of frontiers themselves. Makan Mutua for example, criticizes the doctrine on the grounds that its application prevents the colonized people from exercising their right to self-determination, and rather allows the colonizers to exercise this right for them. Thus, the understanding of a general practice as ‘accepted’, is undeniably exclusive, and needs to accommodate the role of TW states.

Should CIL entail more than general acceptance through the coordination of states?

As per Hartian theory, rules in modern domestic legal systems derive their validity from a rule of recognition that derives its authoritative power from general acceptance. Thus, barring the rule of recognition, all other rules must derive their validity from within the law itself. The same cannot be applied to CIL, as all the rules of CIL derive their authoritative power from general acceptance reported through the coordination of states. The previous section criticized the interpretation of this acceptance, for being too exclusive. This section criticizes the standard, for not being a sufficient condition to ensure the procedural legitimacy of CIL. While general acceptance remains a necessary condition, at the same time, a deliberative process, or some standard employing reasoning, should supplement the acceptance of a rule as CIL.

In this respect, the material sources of CIL must be considered. Only then can the substantive basis of the law be discerned, and then normatively assessed.

Formal sources of law refer to those processes through which rules gain legal status, whereas material sources refer to the extralegal origins of rules, which may be political, social, cultural, economic, moral, or religious. The formal sources of CIL are evidence of state practice and opinio juris. This alone, however, can only answer the question of what CIL is, and cannot make any normative claims as to its content. TWAIL posits that the material sources of CIL are eurocentric, however, this analysis can only be undertaken once it is established that material sources of law are in fact relevant.

For example, the historic origins of uti possidetis can be found in Roman Law. It was an edict issued by the praetor in the initial stages of litigation, conferring provisional possession of property to one party, when two parties claimed ownership of the same property.

This doctrine was dually modified when applied to IL. First, it was applied to the determination of territorial sovereignty rather than private ownership of land; and, second, it was no longer provisional, as the borders drawn by colonizers became permanent international borders.

Therefore, the application of this doctrine in a context that was not analogous to the one in which it was created, is questionable, and inadequately supported by any explicit reason. Implicit reasons such as the incentive to create an international legal order compatible with European culture, maintain the status quo in terms of existing power structures among states and a lack of regard to the people of the colonized states in relation to the larger goal of ‘international stability’ can only be inferred. Further, the imposition of a Roman doctrine, created without considering pre-colonial Asia, Africa or Latin America, to their vastly differing cultures and social contexts raises questions as to its legitimacy.

A Reconceptualization of CIL

Gerald Postema postulates that ‘the hallmark of legally binding custom … is not the addition of belief or conviction to behavior, but rather the integration of meaningful conduct into a web of legally recognized reasons and arguments.’ Custom, therefore, should arise from discursive normative practices. Thus, a CIL rule is established not by repetition of certain practice or beliefs, but rather, due to its integration into the normative framework of the body of law. This integration is evaluated on the basis of whether the customary norm, is by reason and argument, internal to the system of normative practice, such that it finds a place within it. In other words, in addition to being empirically proven, the rule needs to be checked against the normative standard inherent in the law. This process can be practically adopted by conferring greater weightage to general assembly discussions and resolutions and increasing participation and significance of international organizations within the discourse of IL which results in greater scope of argumentation and normative analysis than merely empirical evidence.

This might seem relatively futile, if it were conceded that the normative standard of the IL, as a whole, favours the West at the cost of the exclusion of the TW. However, this will at least, through the process of deliberative reasoning, help to clarify and realize the normative standards of IL that are otherwise obscure. Additionally, this deliberative process puts greater importance on the substantive argument supporting the norm, as opposed to the political power exercised by the state supporting it. Further, discourse surrounding these standards is a necessary step towards their transformation into standards that account for the diversity in the international community.

Deliberative reasoning would also allow for normative standards that consider the interests of humanity to be prioritized over those of individual, developed states. This was done by J. Trindade when he interpreted the norm of nuclear disarmament as a customary rule, by adjudging the universal juridical conscience of mankind to stand well above the ‘will’ of individual states (Marshall Islands v. India, 2016 ICJ Rep. 435 ¶312). Applying this to uti possidetis, one might consider the human rights and right of self-determination to stand above that of the objective of the colonizer state. Thus, in IL this could involve a more inclusive and deliberative process of lawmaking that would make better outcomes more likely to be achieved.


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