A Rose by any other name: The Secret Life of Novation in International Law

[Moisés A. Montiel is a Venezuelan-Mexican international lawyer, focusing on the law of sources and teaching international law at Centro de Investigación y Docencia Económicas at Mexico City]

For nearly sixty years, the parties to the Guyana-Venezuela controversy have disagreed not only about who owns the Esequibo, but about what the dispute between them actually entails. The submission of this controversy to the International Court of Justice has highlighted the stark contrast between the parties’ framing of the issue itself and revealed a structural shortcoming for settling that very point.

Guyana’s position is straightforward: The 1899 Arbitral Award validly determined the boundary, the Geneva Agreement of 1966 merely established procedures to address Venezuela’s political dissatisfaction with that settled frontier, and the Court’s task is to confirm the validity of the Award. Venezuela’s framing is fundamentally different. For Venezuela, by expressly recognizing the existence of a controversy concerning the Award and requiring the parties to seek a “practical and mutually satisfactory settlement,” the Geneva Agreement transformed the legal framework and the dispute itself. The controversy ceased to be merely about validating an arbitral award and became a broader territorial controversy governed by a different normative architecture.

It was while listening to Professor Makane Moïse Mbengue defend this latter proposition before the Court that an oddly familiar structure emerged. According to Mbengue, the Agreement displaced the issue from the narrow terrain of the awards’ validation toward the broader border dispute itself. In this view, the Agreement forecloses Guyana’s ambitions to simply reaffirm the Award by means of an instrument whose explicit aim is to achieve a “practical” and “mutually satisfactory” settlement beyond the preexisting framework of the Award.

Civil lawyers have a name for that operation: novation.

The argument was notable because international law has been historically wary of describing the operation invoked by Venezuela. Mbengue used the term cautiously, recognizing that it was undertheorized in international law, and it is yet to be seen if the Court will adopt the doctrine explicitly. Nevertheless, the structure of the argument was unmissable for any civil law-trained practitioner: the extinction of the previous legal framework, the creation of a new legal relationship, and the explicit intention to substitute one normative architecture for another.

This commentary posits that this wariness is curious because international law, in fact, constantly undertakes novation-like operations even if it calls them by any other name. Several doctrines and practices in international legal doctrine are permeated by fragmented proxies for what are, in essence, arguments about legal regime substitution. International jurists adopt synonyms like supersession, tacit termination, succession of states, estoppel, lex posterioris, acquiescence, consolidation, or subsequent agreements. Underlying this doctrinal lexicon is a recurring structural question: when does a subsequent juridical framework simply regulate an already existing situation and when does it replace it?

The question is not merely semantic. It goes to the very architecture of authority in international law.

In Roman law, novatio referred to the extinction of a prior obligation by means of the creation of a new one purposely designed to replace the former. Novation is neither mere modification nor overlap between coexisting frameworks. It requires legal substitution.

Modern contract law generally understands novation as the consensual replacement of one legal relationship by another. Rather than modifying an existing obligation, novation extinguishes it and provides a new juridical framework intended to occupy its place. Roman law supplied the concept; modern private law refined its operation. Novation, then, serves a precise function. Unlike amendment or modification, it does not preserve the original legal relationship while altering its terms. Rather, it extinguishes that relationship and substitutes another, allocating rights, obligations, and legal consequences to a new juridical framework. It is, fundamentally, a doctrine concerned with legal transformation rather than legal continuity in private contract law.

That being said, it bears mentioning that international law is not simply Roman law projected on a global scale. The history of the importation of domestic institutions into international law is one fraught with cautionary tales against analytical indiscipline. Yet, it is precisely because of that track record that the silence surrounding novation speaks volumes. The question is not whether International Law should mechanically transplant the Roman institution of novatio, but rather whether it is already performing operations essentially constituting novation without openly naming them as such.

Recent scholarship has increasingly emphasized that legal concepts often migrate across doctrinal settings while performing analogous structural functions. The question, then, is not one of mechanical transplantation, but of juridical translation. From this perspective, the recent work of the International Law Commission on General Principles of International Law becomes required reading. The ILC correctly emphasized that principles derived from domestic legal systems require abstraction and systemic compatibility before being admissible in international parlance. The Commission cautioned against the wholesale smuggling of general principles like contraband hidden under the aegis of article 38(1)(c) of the Statute of the ICJ. But it did recognize something important: international law routinely absorbs legal technologies developed in domestic systems at higher levels of generality.

At that level of abstraction, novation begins to look a lot less like a foreign intruder and more like a latent operation that international law already carries out under different names, as Mbengue argued was the case with the Geneva Agreement. More to the point, international jurisprudence is ripe with controversies marked by the question of juridical transformation.

Consider the jurisprudence of the Court when it comes to decolonization. In Western Sahara, the ICJ analyzed if precolonial loyalties and historic agreements survived self-determination as the organizing normative framework governing territorial status (see paras. 54-59 and 149-162). In Namibia, the Court grappled with the transformation of the League of Nations’ mandate system into the UN’s decolonization architecture (see paras. 52-53, 80-89, and 118). In Chagos, the Court again approached decolonization not only as an additional layer to prior imperial agreements, but as a normative framework fundamentally altering the legal evaluation of said agreements (see paras. 144 and 149-150). It is noteworthy that none of these opinions employ the language of novation. However, they all revolve around the same structural question: when does a subsequent normative framework simply contextualize a prior legal relationship, and when does it fundamentally alter the obligations due inter partes?

That same anxiety is markedly present in treaty law. The Vienna Convention on the Law of Treaties contains doctrines relative to tacit termination, suspension, incompatibility and even subsequent agreements. Article 59 envisages situations in which parties intend that a later treaty regulate situations governed by a prior agreement. Nevertheless, international law insists on doctrinally fragmenting these undertakings, treating them as isolated technical mechanisms rather than aspects of a larger legal phenomenon. The jurisprudence of the Court has also dealt with these discomforts. In Gabcikovo-Nagymaros, it struggled to navigate the collapse of the political conditions underpinning the original treaty framework. Throughout the ruling, the Court oscillated between continuity and rupture, resisting the total extinction while simultaneously upholding that the normative context surrounding the treaty relation had fundamentally changed (see paras. 104-112 and 123). In a similar vein, in the Nuclear Test case, unilateral declarations transformed the facts of the controversy to such an extent that the Court deemed that the original controversy had lost operational relevance (see paras. 46 and 55). Again, the Court availed itself of the logic of novation without explicitly invoking it.

Now then, why does this matter?

Because the omission or refusal to conceptualize novation -even if insufficient to predetermine the correctness of Venezuela’s position- create the doctrinal indeterminacy that allows both parties to advance equally intelligible -yet fundamentally incompatible- accounts of what the Geneva Agreement legally accomplished.

International Law constantly encounters legal relations that are neither fully continuous nor fully extinct. Yet, because of the lack of a coherent vocabulary for legal transformation, Courts often default to fragmented proxies. The result is analytical slippage. Questions of transformation are characterized as disputes about interpretation. Questions of substitution are recodified as procedural continuity. Thresholds remain undefined in the name of stability while ultimately undermining it. This gives way to the two very different readings of the controversy over the Esequibo that the Court heard in the oral phase and grounds the parties’ interventions. The disagreement, then, is concerned with the syntax of legal transformation itself.

Did the Geneva Agreement preserve the underlying authority structure of the 1899 Award while adding procedural mechanisms that did not fundamentally alter the nature of the dispute? Or did it create a new normative framework that displaced the prior legal architecture governing the dispute to the point that it became, in fact, a larger and different dispute than the mere question of the validity of the Award? The equal plausibility of the diverging framings of the controversy highlights the need for a conceptual grammar to answer this question.

However, need does not law make and the omission is perhaps explained as a function of international law’s reluctance towards change. Positivism, particularly in its classical international form, operates as a technology of authority with a strong preference for continuity, traceability and disciplined attribution. Authority stems from identifiable chains of consent, recognizable sources, and stable validation procedures. Novation destabilizes this architecture because it forces international law to face moments in which legal relationships are not only interpreted or modified but fundamentally transformed.

Transformation is institutionally unsettling because it disrupts the continuity of attribution. If a subsequent framework can really displace a prior legal structure, then authority no longer derives exclusively from lineage preservation. It derives from the identification of the threshold at which transformation itself becomes legally operative. Precisely because of that, international law tends to recode transformative operations into safer vocabularies. Interpretation is less destabilizing than substitution. Subsequent practice is less disruptive than replacement. Evolution is more manageable than rupture.

But the operations remain.

In fact, a large portion of legal reasoning already rests on inferential judgements regarding transformation. Courts infer whether subsequent conduct reflects continuity or substitution, whether subsequent agreements preserve or replace the prior ones, and whether institutional evolution is inheritance or reconstitution. The problem is that international law lacks a coherent syntax to discipline such inferences.

This absence has consequences. Without a stable architecture for fundamental legal transformation, international adjudication runs the risk of oscillating unpredictably between excessive conservatism and unarticulated rupture. Courts either cling to continuity even when normative structures have drastically changed, or they embrace implicit transformations without acknowledging the thresholds governing them.

The result is a jurisprudence haunted by novation that refuses to speak its name and its byproduct is uncertainty and unpredictability in legal relations, as demonstrated by the equally plausible readings of the Esequibo dispute.

Whether novation ultimately merits recognition as a general principle of law, or merely as a useful organizing concept for understanding legal transformation, is a question international lawyers have surprisingly neglected. The pleadings in Guyana v. Venezuela suggest they may not be able to avoid it much longer.