In international law, interpretation is ubiquitous and is the process through which the interpreter attempts to determine the true meaning of the rule that is being interpreted. Most cases brought before international courts and tribunals deal one way or another with questions of interpretation. This process has been codified in Articles 31-33 of the Vienna Convention on the Law of Treaties (VCLT). Based on these articles, some of the elements that are taken into consideration are the text, and context of the treaty, its object and purpose and the intention of the parties. However, a key issue is that these VCLT articles refer only to interpretation of treaties and not of Customary International Law.
Customary international law (CIL) , in turn, is one of the formal sources of international law and together with treaties are the most important ones, creating binding rules of international law. Some of the most crucial rules of international law started and continue to exist as CIL. The issue with CIL, however, is that it is an unwritten source of international law. Its existence is determined inductively through examination of two elements, state practice and opinio juris (acceptance as law).
Whereas in the application of treaties the process of interpretation is one that always yields a solution, with respect to CIL these rules of interpretation have not been examined. This leads to one of the following two paradoxical scenarios. Either CIL needs to be induced each and every time, by reference to state practice and opinio juris (but this is extremely problematic as it fails to take into account the continued existence, development and manifestation of CIL rules); or, even worse, CIL is asserted by international judges. But assertion, essentially means that international judges create law: they become law-makers and exercise a power to legislate (pouvoir de légiférer). Evidently in the study of CIL there is a critical gap in understanding how CIL can be applied in individual cases once it has been formed. TRICI-Law thus aimed to prove that even in the case of this unwritten source, i.e. customary international law (CIL), there are rules of interpretation similar to those that exist for the interpretation of treaties, and to determine the content of these rules.
TRICI-Law consisted of four Work Packages:
Interpretability of CIL in Theory (WP1)
This WP examined the theoretical validity of CIL being open to interpretation. It did so by examining international legal theory with respect to both CIL and interpretation. It provided answers as to whether and why doctrine and domestic legal practice allow for the interpretation of CIL.
In the context of WP1, 1 Conference & 1 Workshop were organised.
The output of WP1 was: 1 book/thesis, 1 edited volume, 1 special series of articles, 7 articles, 3 blog-posts.
Rules of Interpretation of CIL in International Judicial Practice (WP2)
This WP examined the case-law of international judicial and quasi-judicial bodies, in order to induce from it the rules of interpretation of CIL and their precise content.
In the context of WP2, 2 Conferences, 1 Seminar & 1 Workshop were organised.
The output of WP2 was: 1 book/thesis, 1 edited volume, 1 special issue, 8 articles, 1 blog-post.
Convergence/Divergence of Rules of Interpretation and their Evolution through Time (WP3)
This WP examined points of convergence/divergence between the rules of interpretation of CIL and those of treaties and of unilateral acts. It provided answers as to what the similarities and the differences are in both the nature and the content of these rules and inquired into the reasons that may explain these points of convergence/divergence.
In the context of WP3, 1 Conference & 2 Workshops were organised.
The output of WP3 was: 1 online handbook, 1 edited volume, 2 special issues, 15 articles.
Articles/Guidelines on Interpretation of CIL with Commentary (WP4)
WP4 was a synthesis WP, bringing together all the findings of the previous WPs, and condensed them in a single, user-friendly document. That document is in the form of draft Guiding Principles on the interpretation of rules of CIL and was accompanied by a more extensive article-by-article commentary.
In the context of WP4, 2 Conferences & 3 Workshops were organised.
The output of WP4 was: 1 online set of Draft Guiding Principles with Commentaries, 2 books, 1 comic-book, 2 edited volumes, 1 video animation, 9 articles & 1 blog-post
