This article is a translated version of the original piece published in La Hora on June 14.
In a previous article, I explained why the recent ruling by Guatemala’s Constitutional Court (CC), which puts on “hold” the lifting of the reservation to Article 27 of the Vienna Convention on the Law of Treaties (VCLT), is deeply problematic.
In brief, Article 27 enshrines a fundamental principle of customary international law: no State may invoke its internal law as justification for failing to perform a treaty. The reservation Guatemala intended to withdraw had stated that “internal law” did not include its Constitution.
The Constitutional Court, in its ruling, held that the Constitution—as the supreme norm—cannot be subordinated to any other legal instrument. So far, so good. The error, as I previously noted, lies in conflating the domestic legal order with the international one. While the Constitution does indeed sit at the top of Guatemala’s internal legal hierarchy, that supremacy cannot be extended into the international sphere to justify non-compliance with treaty obligations. Yet the Court argues precisely that: that even in international law, the Guatemalan Constitution must prevail over any treaty.
This assertion is not only a serious legal blunder, but one that could have far-reaching implications for Guatemala’s international credibility, especially in the realm of foreign investment. Beyond being wrong under international law, the message it sends is deeply troubling: Guatemala reserves the right to violate treaties if it deems them incompatible with its Constitution.
Let’s consider the practical implications. Which constitutional provisions does this reservation refer to? All of them. With 281 articles in the Constitution, how does one explain to a foreign investor that Guatemala may disregard international commitments by invoking any one of those provisions?
The contrast with other countries is striking. When the United States ratified the International Covenant on Civil and Political Rights, for instance, it limited its reservations to specific constitutional provisions. One such reservation targeted Article 20 of the Covenant—which prohibits war propaganda and advocacy of national, racial, or religious hatred. Although the Covenant allows certain restrictions on freedom of expression, the First Amendment to the U.S. Constitution offers broader protections: it prohibits any such limitations, even on offensive or controversial speech. While these reservations were controversial and drew international criticism, they were narrowly tailored to specific provisions of the Constitution that directly conflicted with individual treaty norms.
Guatemala’s approach is entirely different. Both the original reservation and the CC’s interpretation subject the application of any treaty to the entirety of the Constitution. What message does this send to an investor relying on protections under a bilateral investment treaty (BIT)? If a dispute arises, the Constitutional Court essentially endorses the view that no part of any treaty can supersede any part of the Constitution, regardless of the context.
And it’s not just investment treaties at stake. Many international agreements—while not specifically aimed at investment protection—have major implications for legal certainty and economic stability. Take, for instance, the recent cooperation agreement between Guatemala and the United States to modernize Puerto Quetzal. This 30-year accord encompasses logistics development and security collaboration. Can we truly guarantee that Guatemala won’t later invoke some constitutional interpretation to walk away from those commitments? The CC’s ruling leaves that door wide open, injecting uncertainty even into long-term strategic partnerships.
For those unfamiliar with the subject, BITs are treaties between States that aim to provide legal guarantees to foreign investors. Their purpose is to shield investments from arbitrary state actions, offering assurances such as fair and equitable treatment, protection against expropriation without compensation, and access to effective dispute resolution mechanisms. A key feature of these treaties is international arbitration, allowing investors to sue the host State directly—bypassing local courts. This mechanism, intended to reduce legal risk and attract capital, becomes almost meaningless if a State like Guatemala reserves the right to subordinate treaties to its Constitution. As of today, Guatemala faces international claims exceeding US$1.081 billion and has already been ordered to pay US$64.5 million in one such arbitration. In this scenario, arbitration stops being a protective mechanism and becomes a hollow formality, subject to the whims of constitutional interpretation.
How can any investor be confident that an arbitral award will be enforced if the Constitutional Court has already opened the door for Guatemala to ignore such awards based on alleged constitutional conflicts?
The stakes go beyond investors. This posture could have serious consequences for Guatemala as a State. In an extreme case, if the country refuses to comply with an arbitral ruling by invoking domestic law, other States could consider it a breach of international law. Under the principles codified in the Articles on Responsibility of States for Internationally Wrongful Acts, such conduct could justify legal countermeasures—ranging from trade restrictions to barriers on Guatemalan investments abroad. A doctrine that legitimizes treaty violations—as the CC’s ruling effectively does—could ultimately backfire. Instead of bolstering sovereignty, it would weaken the country’s standing in the international community.
A relevant example is the case of LG&E v. Argentine Republic, decided by an ICSID arbitral tribunal. In that case, Argentina argued that, due to domestic laws and a financial crisis, it could not fulfill its obligations under a BIT. However, the tribunal clarified that under Article 42(1) of the ICSID Convention, it had to apply both domestic and international law, giving precedence to international law in the event of a conflict.
This view stands in stark contrast to the Guatemalan Constitutional Court’s position, which seeks to impose constitutional supremacy even at the international level. This clearly contradicts the customary law principle reflected in Article 27 of the Vienna Convention: no State may invoke its internal law to justify treaty breaches.
There is still time to reverse course. The Court’s ruling was issued in the context of a provisional injunction. A final decision is yet to come. Hopefully, when that time arrives, the Constitutional Court will reconsider and abandon this dangerously flawed doctrine. Persisting in this interpretation not only undermines Guatemala’s international legal commitments but injects a high level of legal uncertainty—one that could carry a steep cost. Reversing it would be the prudent, and lawful, course of action.
