3.3. Sources of international law

Less time needs to be spent discussing the sources of international law than was spent on discussing its actors or subjects. In fact international relations theorists do not even employ a concept of the sources of international law, distinct from the actors who constitute it.[1]

International lawyers on the other hand, having traditionally decreed that states were the only subjects of international law, accordingly determined that international treaties and customary law to which state consent could be traced were its only sources.[2]

The conceptual usefulness of such a narrow view has been limited, even leaving aside most of the implications of new medievalism, and accordingly scholars have found it necessary to expand it. They have done this by drawing a distinction between hard law and soft law, as briefly alluded to in the Introduction.[3]

As might be expected, the divide between hard law and soft law is in reality a continuum. One group of authors has defined three variables of obligation, precision, and delegation by which the hardness or “legalisation” of international law can be measured.[4] Obligation is the extent to which the compliance or non-compliance of states (or, as a slight gloss, international actors) with a rule is subject to scrutiny by international and/or domestic legal institutions. Precision is the degree to which the rule in question is capable of expression in a certain and unambiguous form. Delegation exists where a neutral body has been authorised to implement (for example, to interpret or enforce) the rule in question.

An example of international law which is high on every dimension is the TRIPS convention: it is strongly obligatory, being enforceable through the WTO’s Dispute Settlement Process, it is drafted with a high degree of precision, and the determination of a state’s compliance or otherwise with the convention has been delegated to the Dispute Settlement Body.

An example which is low on every dimension is the obligation that participants in WSIS assumed when they agreed, for example, to “commit ourselves to promote the inclusion of all peoples in the Information Society through the development and use of local and/or indigenous languages in ICTs.”[5] The compliance of individual states with this undertaking is not monitored, the content of the obligation is highly imprecise, and although there is a WSIS follow-up process, no legal consequences flow from it for participants who fail to implement the commitment.



Cutler, A C, Private Power and Global Authority: Transnational Merchant Law in the Global Political Economy (2003), 77


Cutler, A C, Private Power and Global Authority: Transnational Merchant Law in the Global Political Economy (2003), 21


See Section 1.4.1.


Abbot, Kenneth W, Keohane, Robert O, Moravcsik, Andrew, Slaughter, Anne-Marie, & Snidal, Duncan, The Concept of Legalization (2000), 404–406


WSIS, Tunis Commitment (2005), paragraph 32