The FTO designation increases the likelihood that the Trump administration takes unilateral action to apply lethal force against cartel members. This raises questions under both international and domestic law.
To date, the United States has not openly used lethal force in Mexico.[1] But talk of it is intensifying. On April 8, 2025, NBC News reported that senior Trump Administration officials were openly discussing the possibility of using drone strike to kill cartel members inside Mexico. On April 30, CNN reported that the Administration was similarly considering labeling cartel members “enemy combatants,” much like the Bush Administration did for members of the Taliban during the War on Terror. This may be a step to legally justify lethal strikes.
So far, the Mexican government has explicitly rejected these proposals. On May 3, 2025, Mexican President Claudia Sheinbaum pushed back on the latest set of rumors. Speaking to a crowd in Mexico, she insisted that any U.S. presence or use of force would infringe on Mexican sovereignty. “It’s not necessary. We can collaborate.”
Indeed, it appears that Mexican collaboration is the reason why, to this point, the hawks within the Trump Administration have been assuaged. Mexico has been largely responsive the Trump’s emphasis on fighting the cartels. On February 27, 2025, Sheinbaum authorized the largest single-day extradition of cartel leaders to the U.S., transferring 29 top figures including Rafael Caro Quintero and two senior leaders of Los Zetas. This step was legally questionable under Mexican law. But there are rumors that she intends to go for a second round.
Reports indicate that those within the Trump Administration who caution against unilateral strikes are doing so out of a fear that doing so will jeopardize Mexico’s cooperation. This fear is well-founded if President Sheinbaum can be taken at her word. But beyond the practicality of such a step, the legality of unilateral strikes is not clearly permitted under international or domestic law.
Unilateral strikes may be illegal under international law. The case for their domestic legality is stronger but has weaknesses.
Under the United Nations Charter, countries are generally prohibited from engaging in armed conflict. Article 51 provides an exception for self-defense. If the United States were to use force unilaterally against the cartels, it would likely do so by seeking to invoke this exception (the Art. 42 path is unavailable as a practical matter).
The argument that the United States would employ would rely on the concept of anticipatory self-defense. The argument relies on the premise that sovereigns are responsible for violence emanating from its territory. Failing that responsibility enables other states to act in self-defense. The United States most recently invoked this argument to strike militants in Syria in 2021. The United States saw this as a “necessary and proportionate action” to a legitimate and dangerous threat in an area where the government was “unwilling or unable to prevent the use of its territory by non-state militia groups responsible for such attacks.”
The Trump administration appears to be setting the stage to similarly justify striking cartels in Mexico. It should proceed carefully. For all its instability, Mexico in 2025 does not resemble Syria in 2021. The state remains stable even if it has trouble with internal stability. More than that, equating sometimes disparate groups of drug and human traffickers along the border with territory-holding militias in Syria is a logical leap. And at a bigger picture, arguing “unwilling and unable” in the current context would signal a substantial expansion of the doctrine.
At a more fundamental level, this argument assumes a state of armed conflict. The case for one on the border is hard to make. Cartels are not deliberately attacking the United States, even if their actions produce negative externalities that the United States experiences. And even if there was a state of armed conflict, it would not be clear that targeting cartel members with lethal force would be permissible under the international humanitarian law—the legal regime governing state conduct during armed conflict.
This leaves to one side the legality of these strikes under domestic law. The President’s authority to conduct strikes is broad but not unlimited. Granted, he does have plenary power to “protect and defend” the United States as the commander in chief in whom the Executive Power is vested. But Congress alone has the power to declare war. The War Powers Resolution entitles the President to engage in hostilities without Congressional consent. But he can only do so on a temporary basis, and even then, only in the case of “a national emergency created by attack upon the United States . . . .” At least one court has already held that the actions of Tren de Aragua—a Venezuela group that Trump designated as foreign terrorist organization alongside the Mexican cartels—do not constitute an attack on the United States.
But the CIA is reportedly drawing up a list of targets. It seems like the Administration is reaching for a tool that it is familiar with from the War on Terror. But it may be better off considering a different approach.
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[1] The United States government maintains a robust covert action capacity through the Central Intelligence Agency. See National Security Act of 1947, Pub. L. No. 80-253, 61 Stat. 495 (describing the “Fifth Function” of the CIA). This capability is subject to strict Congressional oversight. See generally 50 U.S.C. § 3091 (laying out Congressional control of covert action programs). Given the clandestine nature of these programs, it is possible that the United States has used lethal force against the cartels previousl.