The Silala Case: Was Justice Served?

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On 1 December 2022, the International Court of Justice (“ICJ” or “Court”) issued its decision on the Silala case. At the time of the Application, the Parties’ views were positively opposed. Chile requested a declaratory judgment that the Silala River system is an international watercourse, the use of which is governed by customary international law (“CIL”). It furthermore sought a declaration recognizing that its current use of the water is equitable and reasonable. Bolivia, on the other hand, rejected Chile’s legal characterization of the Silala, arguing instead that it was a spring wholly located in Bolivian territory and artificially steered towards Chile (Judgment, para. 32).

While Chile’s claims remained essentially untouched throughout the proceedings (Judgment, paras. 25, 27), Bolivia progressively modified its submissions and, in its closing arguments, presented a radically different case – that all of the Silala, including any artificially enhanced surface flow, constitutes an international watercourse that entitles both States to an equitable and reasonable use.

In light of these evolving positions, the Court “carefully assess[ed] whether and to what extent the final submissions of the Parties continue to reflect a dispute between them” (Judgment, para. 43, citing Nuclear Tests, para. 29, which recognized this task as an attribute of its judicial function). The Court frequently interprets the parties’ claims. Yet, its effort to find “agreements” or “convergences” between Chile and Bolivia’s claims – to determine if they still had an object – was rather unusual. As Judge Charlesworth reasoned, the Court took an “impressionistic approach”, which entirely overlooked the Parties’ submissions (Charlesworth’s Declaration, para. 18).

The Slippery Interpretation of the Parties’ Submissions

Despite the Applicant’s emphatic request for a declaratory judgment – to prevent the Respondent from changing its positions in the future (Judgement, para. 44, para. 61) – the Court went under tremendous pains to interpret the Parties’ contentions towards convergence so that “there [was] no call for a declaratory judgment”. Yet, the record is at least ambiguous in this regard. 

  • Both Parties undoubtedly recognized that the Silala is an international watercourse, but there was divergence regarding the definition of an international watercourse under CIL (Judgment, para 92) and the specific effects of the “artificially enhanced” flow in determining what constitutes an equitable and reasonable utilization (Judgment, para 57). Surprisingly, the Court disregarded these divergences and found that the Parties simply “agreed”.
  • Chile requested, quite specifically in submission (c), a declaration that its current use of the water is in conformity with CIL (Judgment, paras. 67, 72). Bolivia, in response, requested the Court to declare that Chile’s current use is without prejudice to Bolivia’s coexisting rights (Judgment, para. 69). On its face, these two submissions are rather different, but the Court again found that the Parties “agreed” on it.
  • Chile objected to the Court’s jurisdiction on Bolivia’s first counter-claim (Judgment, para. 39), but the Court, in a surprising move, denied that such an objection existed (Judgment, para 134), based on a letter dealing with admissibility and not jurisdiction (Judgment, para 133). The Court found this despite Chile maintaining its jurisdictional objection through the end of the oral hearings.
  • Finally, there is the so-called convergence regarding Bolivia’s second counter-claim, which is addressed by Judge ad-hoc Simma in his Separate Opinion. In Judge Simma’s view, Bolivia’s second counter-claim sought a declaration that Chile could not use the “artificial flows” without Bolivia’s consent. This contention became untenable when Bolivia acknowledged that Chile’s right to make equitable and reasonable use of the waters covered the entirety of the waters, including the “enhanced flow” (Judgment, para. 63). The Court, instead of rejecting the counter-claim, concluded it no longer had an object (Simma’s Separate Opinion, paras. 14, 15, 16).

In the absence of a declaratory judgment on the claims and counter-claims actually submitted by the Parties, the Court (facilitated by slippery interpretation) positively took note of the existence of “agreements” or “convergence” of views with respect to most issues. That is the reality both Parties face today.

The Legal Effect of “Agreements” and “Convergence”

After concluding that the Parties “ha[d] come to agree in substance” (Judgment, para. 46), the ICJ held, as a consequence thereof, that those claims and counter-claims “no longer ha[d] any object” (Judgment, para. 163). It is enigmatic that, in the Court’s view, the legal effect of party “A” agreeing to the claims of party “B” is to render the claim without an object, when the most reasonable outcome should be to decide the dispute in favor of the party making the claim to which the other party now acceded.

Neither did the Court, as Judges Charlesworth and Simma suggest, record the “agreements” in the Decision’s operative clauses. This would have categorically resolved the controversy and disposed of the dispute (see below). Instead, the ICJ decided not to decide. It merely “took note” of the existence of “agreements” on points of law and fact, and then concluded that the claims had become without an object. While judicially-recognized “agreements” should not be devoid of legal effect, some uncertainty remains. How can Chile enforce its agreement of views vis-a-vis Bolivia? In turn, is Bolivia subject to any legal obligations, and what is their scope?

First, the Judgment does not seem to answer, on its face, these questions. As noted, the Parties’ “agreements” are not mentioned in the operative clauses (Judgment, para. 163), which have the force of res judicata (see, among others, Free Zones para. 13, Awards of Compensation, para. 47, Maritime Delimitation, para. 13). In Bosnian Genocide, the Court determined that issues decided with the force of res judicata are those “necessarily entailed in the decision of those issues”, whereas the obiter dicta refers to peripheral or subsidiary matters (para 126). While the “agreements” between Chile and Bolivia were not peripheral or subsidiary to the issues discussed – because they were determinative to the decision of the ICJ – the Court’s jurisprudence constante on the matter does not fully clarify its legal effect.

However, there is room to argue that the ICJ’s recognition of these “agreements” is binding upon the Parties. For instance, in Request for Interpretation of the Temple the Court noted that res judicata might attach to the statements of reason contained in a judgment as long as those reasons are “inseparable from the operative clauses” (para. 34). Unfortunately, more recent decisions by the Court seem to see statements of reasons as mere limits to the operative clauses, or as tools to interpret the latter, rather than as potentially binding statements (see Questions of Delimitation between Nicaragua and Colombia at 61). Ultimately, there is no decisive case law establishing the value that statements of reason closely connected to, or upon which the operative clauses are built, have (for further on this topic, see here). And the ICJ lost its opportunity to clear the issue.

Second, the Parties could find relief in other sources of international law. The “agreements” noted by the Court may give rise to newly created treaty-based obligations. Obligations on this base may arise in the course of judicial proceedings, need not be written, are irrespective of their form, and may even be concluded tacitly, as long as there is an intention of the parties to establish rights and obligations (see, among others, Obligation to Negotiate, para. 97, Maritime Delimitation in the Indian Ocean, para. 37). Such intention is determined by reference to an “instrument’s terms and the particular circumstances of its adoption” (see South China Sea Arbitration, para. 213), or by the animus contrahendi inferred by their conduct.

Alternatively, the parties could rely on unilateral statements expressed by the other in the course of the proceedings and seek protection under the principle of estoppel. According to this principle, given that Chile relied on Bolivia’s statements throughout the proceedings – statements which lead the Court to find that the parties “agreed” – if Bolivia then changes its position to Chile’s detriment, the latter could ask the Court to find that Bolivia was precluded from acting in such a way (see, among others, North Sea Continental Shelf Case at 30, Preliminary Objections in the Nicaragua Case at 51, Preliminary Objections in the Land and Maritime Boundary Case between Cameroon and Nigeria at 57). And the Court’s decision contains some statements that would favor this approach, as Judge Charlesworth identifies in her declaration (Charlesworth’s Declaration, para. 15). Relevantly, the ICJ presumed the parties act in good faith when making statements before it, and noted that parties accept the soundness of their counterparties’ arguments (Judgment, paras. 46, 58, 75). The Court went further and even noted, as an example, that “Bolivia may rely on Chile’s acceptance of Bolivia’s right to dismantle the channels” (Judgment, para. 146).

It is unhelpful for both parties that the Court didn’t find, as it did in Nuclear Tests, that the parties’ dispute disappeared because the “object of the claim ha[d] been achieved” through these “agreements”. Instead, it found that the claim no longer had an object (see Charlesworth’s Declaration, para. 13-14). The latter makes it harder to find, within the Decision, a positive recognition by the Court that the “agreements” gave rise to treaty-based obligations or unilateral acts, because if they did, the object of the claim would have been achieved and not lost by means of a new legal undertaking.

Nevertheless, the Parties are free to argue that agreements or unilateral acts bind their neighbor independent from the Court’s operative decision and could benefit from the preambulatory paragraphs of the Judgement that appear declaratory in nature (see Judgment, para. 92-94).

Final Remarks

As noted by Judge Tomka, “it remains to be seen what useful role, if any, this Judgment will play in the relations between Chile and Bolivia” (Tomka’s Declaration, para. 4). While his words resonate, the proceedings before the Court proved useful. Following the reading of the Decision, Chile and Bolivia declared that the dispute had been resolved and disposed of.

In 2016, Chile stood against a Respondent that denied every single claim. In 2022, it stands next to a Respondent that relinquished its initial position and publicly recognized that Chile’s submissions were right in law and fact. Bolivia has so publicly changed its views, upon which Chile now relies, that it will be difficult, if not impossible, to go back. Bolivia itself has confirmed this in recent days. Unfortunately, the agreed-upon views were not embraced by the Court in the operative decision nor positively recognized as giving rise to independent sources of obligations. The resolution is instead a consequence of the Parties’ own conduct during the proceedings and, while weighty, is not bulletproof to subsequent changes in their conduct. It remains to be seen how the Parties will enforce their “agreements” and on what legal basis.  

The views expressed in this piece reflect the personal views of the authors and do not, in any way, represent the views of the organizations with which they are or have been affiliated with. In particular, they do not represent the views of the Republic of Chile.

Benjamin Salas Kantor was a legal advisor to Chile in the Dispute over the Status and Use of the Waters of the Silala (Chile v. Bolivia) during the years 2016 to 2018.

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Nicolas Boeglin says

December 9, 2022

Dear colleagues

Many thanks for this extremely valuable post. As an additional point concerning the perplexity caused by this strange "judgement", I would also refer you to the conclusion of Chile´s Judge Ad Hoc, Bruno Simma, in his separate opinion:

"The Court owes it to the parties
to render well-reasoned judgments which settle their disputes with binding force, and, where
appropriate, offers them guidance on their rights and obligations. Reflecting on the Court’s
deliberative process, the then President of the Permanent Court of International Justice, Max Huber,
once compared the Court’s decisions to “ships which are intended to be launched on the high seas of
international criticism”12. It is a pity that today the Court chose to launch an empty vessel".


Yours sincerely

Nicolas Boeglin