Has the U.S. Operation Against Maduro Changed the Prohibition on the Use of Force?

[Matei Alexianu is an Associate at Foley Hoag LLP. He is a graduate of Yale Law School and recipient of the Diploma of the Hague Academy of International Law. The views expressed in his articles do not necessarily reflect the views of any institution with which he is or has been affiliated]

In the first year of the second Trump administration, the United States has repeatedly violated the U.N. Charter’s prohibition on the threat or use of force. Prior to the U.S.-Israeli attack on Iran launched on February 28, 2026, perhaps the most notable example was the U.S.’s “extraordinary rendition” operation against Venezuelan President Nicolás Maduro. On January 3, 2026, U.S. forces conducted a military strike in Caracas, capturing Maduro and his wife, Cilia Flores, and transporting them to New York to face narco-terrorism charges.

Despite the operation’s patent illegality, the international response has been mixed. While many States, particularly in Latin America, Africa, and Asia, condemned the operation as a clear violation of international law, others took an ambiguous or even supportive stance. U.K. Prime Minister Keir Starmer cryptically stated:

“The UK has long supported a transition of power in Venezuela. We regarded Maduro as an illegitimate President and we shed no tears about the end of his regime. I reiterated my support for international law this morning.”

Two months later, it is worth taking stock of the effect of the U.S. operation and the international community’s response on the scope of the international law prohibition on the use of force. (The operation and subsequent U.S. conduct with respect to Venezuela also violate other rules of international law, such as the customary non-intervention principle, but these are beyond the scope of this piece.) In terms of the rule against the use of force, there are three possibilities. First, the operation could have constituted a breach of the prohibition that has left the rule intact. Second, the operation and State reactions to it could have narrowed the scope of the prohibition by introducing a new customary exception to its application. This is what some scholars argued—albeit controversially—occurred in the cases of the “unwilling and unable” doctrine and humanitarian intervention. Finally, and most dramatically, the operation and ensuing international response could have marked the end of the customary prohibition on the use of force, a process called desuetude.

In this short article, I argue that the U.S.’s lack of legal justification and vocal opposition by most States means that the content of the rule remains intact for now. Nevertheless, this episode of aggression raises serious concerns about the normative force of the rule—concerns further exacerbated by recent developments in the Middle East.

The Role of Justifications and State Reactions in the Jus Ad Bellum

The rules governing the use of armed force internationally, the jus ad bellum, are rooted in both the U.N. Charter and customary international law. Article 2(4) of the U.N. Charter prohibits “the threat or use of force against the territorial integrity or political independence of any state.” This prohibition has only two explicit exceptions: self-defense if an armed attack occurs against a State, and force authorized by the U.N. Security Council. State consent to armed intervention is a third exception to the prohibition.

The overlapping, and arguably identical, scope of the treaty and customary obligations gives rise to some technical complications, but in the interests of simplicity the analysis here focuses on the customary prohibition on the use of force, which is arguably more dynamic and applies to all States.

Customary international law rules can change over time if enough States agree to the change. This can even occur when a State violates a customary rule. The International Court of Justice recognized this in its Nicaragua judgment in the analogous context of the customary rule of non-intervention (para. 207):

“The significance for the Court of cases of State conduct prima facie inconsistent with the principle of non-intervention lies in the nature of the ground offered as justification. Reliance by a State on a novel right or an unprecedented exception to the principle might, if shared in principle by other States, tend towards a modification of customary international law.”

Thus, a breach of a customary rule can trigger a change in the law when the breaching State justifies the breach according to a new right or exception and the change is supported by other States.

What level and kind of support is needed? Although neither the ICJ nor the International Law Commission (ILC) have specifically addressed the issue of modification of customary rules, the two-element test for identification of custom likely applies. The ICJ has held that customary international consists of a general practice, accepted as law (opinio juris). Notably, State practice must be “both extensive and virtually uniform.” As for opinio juris, the ILC has concluded that “it is broad and representative acceptance, together with no or little objection, that is required.”

There is an additional wrinkle when analyzing the evolution of the prohibition on the use of force, and in particular the prohibition on aggression—the “most serious and dangerous form of the illegal use of force.” The rule against aggression is a peremptory norm of international law (jus cogens), that is, a fundamental norm from which no derogation is permitted. This characteristic imposes an especially high threshold for its modification. There is, however, some academic debate about whether the self-defense exception to the use of force is also jus cogens. To be on the safe side, the analysis here conservatively applies the lower threshold of modification for non-peremptory customary international law.

Rules of customary international law can also terminate through desuetude. It is unclear whether only one or both of the elements of customary international law must be lost over time for this to happen. In any case, terminating a customary rule requires more than occasional inconsistent practice, which merely indicates a breach of the existing rule. If enough States continue to follow the existing rule and the deviant behavior is identified as a breach of that rule, the rule endures.

The Maduro Operation: U.S. Justifications and State Responses

Remarkably, the U.S. did not even attempt to justify the operation in terms of the U.N. Charter in its official statement at the U.N. Security Council. Nor did it submit a report to the U.N. Security Council justifying its attack as self-defense under Article 51. Instead, the administration framed it as a “law enforcement operation” against an “indicted drug trafficker.” Although Mike Waltz, the U.S. Ambassador to the U.N., briefly referenced Article 51 in a television interview, this appears to have been a passing remark that was not repeated elsewhere. In a Senate hearing on January 28, Secretary of State Marco Rubio again did not seek to justify the operation in international law terms and insisted on the “law enforcement” framing, which has no plausible basis in international law. This is in line with the administration’s broader rhetoric suggesting that it is unconstrained by international law.

In the absence of any international law justification put forward by the Trump administration, there is no scope for customary international law to evolve. Just as the ICJ concluded in the Nicaragua opinion (para. 207), the U.S. justifications for the Maduro operation are “statements of international policy, and not an assertion of rules of existing international law.” Because the U.S. has not indicated any international law basis for its operation, it has not furnished the requisite opinio juris to accompany its practice.  At the same time, its failure to justify the operation means that it has not proposed a legal interpretation for other States to endorse. This helps explain why even supportive States did not explicitly argue that the operation was legal. Instead, they limited themselves to policy-based arguments in favor of removing Maduro from power. Thus, any supposed effort to modify the jus ad bellum stumbles out of the gate.

One might argue that the Trump administration’s repeated reference to anti-narcotics law enforcement represents an implicit argument about a novel exception to the prohibition on the use of force. Setting aside the issues of the vagueness and implausibility of such a claim, there is little evidence that it has gained the widespread international support required to modify the jus ad bellum. A recent compilation of State reactions to the operation identifies critical responses by  119 States, mixed or neutral reactions by 46 States (including some international organizations), and supportive reactions by 25 States. Notably, at the emergency Security Council meeting immediately following the operation, a representative of the Non-Aligned Movement “categorically condemn[ed] the act of aggression” which “blatantly violate[d]” the U.N. Charter.  Many other States, including Brazil, Chile, Colombia, Mexico, Uruguay, and Spain also took the position that the operation “contravenes fundamental principles of international law.”

In contrast, none of the supportive statements defended the legality of the operation under international law. Instead, States equivocated on the topic. The Greek Prime Minister, for instance, stated:

“The end of [Maduro’s] regime offers new hope for the country. This is not the time to comment on the legality of the recent actions.”

Canada, meanwhile, “welcome[d] the opportunity for freedom, democracy, peace, and prosperity for the Venezuelan people” but “call[ed] on all parties to respect international law.” In short, the international community has clearly not coalesced around a new exception to the prohibition on the use of force, either for narcotrafficking enforcement or otherwise.

The more dramatic possibility is that the U.S. operation is evidence that the prohibition on the use of force is disappearing altogether. It’s worth noting that this prediction has been made many times before. For now, the vociferous opposition by many suggests that this episode is better understood as an individual breach—albeit a highly corrosive one—rather than evidence of the broader collapse of the norm. However, this could change rapidly if the international community accepts future violations as lawful or, even worse, imitates the U.S. example elsewhere.

Conclusion

Two months in, there is little evidence that the illegal U.S. operation against Maduro has loosened the constraints of the international law prohibition on the use of force. To be sure, this is hardly a cause for jubilation. The absence of any attempted legal justification, either by the U.S. or its supporters, is a double-edged sword. On the one hand, it means that the Trump administration has effectively forfeited the international law argument in the face of broad condemnation by the international community. As a result, the “law in books” is unchanged. On the other hand, the refusal to even speak the language of international law means that international law’s status as “law in action” is now at risk. Its future lies in the words (opinio juris) and deeds (State practice) of the international community. Recent developments in the Middle East underscore the stakes involved.

Photo Attribution: “Flag of Venezuela” by Beatrice Murch is licensed under CC BY 2.0