"One of These Things is Not Like the Other": International Law and the Lethal Attack on the Drug Boat
I have had several friends ask me about the legality under international law of the lethal attack of the drug smuggling boat in the Caribbean a few days ago. It certainly violated the norms—in the past the U.S. has used law enforcement tools such as interdiction and not lethal attack on drug smuggling operations. The use of lethal force by the U.S. military was a sharp break from past U.S. practice.
But was it also unlawful under international law? I think it was, but understanding why requires a bit of background.
When I was in law school, Professor Martha Minow, one of my favorite professors who later served as Dean of the Harvard Law School, used to say that most legal issues really boil down to the old Sesame Street song “One of these things is not like the other.” In other words, in many legal questions, the answer depends on how we characterize the problem.
This Sesame Street tool of analysis is critical to the legality of the lethal strikes at issue here. There are some legal principles that apply to almost all circumstances. One example would be Article 2(4) of the United Nations Charter that provides that “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any State, or in any other manner inconsistent with the Purposes of the United Nations.” If the lethal strikes had occurred in the sovereign territory of a nation or on a ship flagged to a nation, this principle would have come into play. Here, however, the attack took place in international waters and the boat does not appear to be flagged by any country. The U.N. Charter, therefore, doesn’t address this issue.
Instead we must look to two very different international legal frameworks and use the Sesame Street principle to decide which framework should apply here. The two frameworks are International Human Rights Law on one hand, and International Humanitarian Law (which I prefer to call by the more descriptive title of the Law of Armed Conflict) on the other.
International Human Rights law developed after the Law of Armed Conflict, and really come to be a force after World War II with the development of the U.N. Declaration of Human Rights and numerous human rights treaties that were signed and ratified by the U.S. It is also reflected in customary international law—which are legal requirements that have been accepted by the large majority of nations.
One of the key principles to come out of both the treaties and customary international law (as accepted by the U.S.) is the ban on extrajudicial killings. For example, Article 3(d) of the First Geneva Convention prohibits carrying out executions without passing a prior judgement by a competent and regularly constituted court with all commonly recognized judicial guarantees for everyone taking part in the trial, and Article 147 of the Geneva Convention of 1949, makes it a grave breach to “wilfully depriving a protected person of the rights of fair and regular trial prescribed in the present Convention.” The United States has itself recognized as customary international law (as reflected in the Department of Defense Operational Law Handbook), the prohibition of murder.
This framework, of course, recognizes that sometimes lethal force may be necessary in policing operations, but only allows it when necessary in self-defense. Critically, this exception depends on the actions of the person attacked at the time. The person’s status as a criminal itself is not enough.
If the International Human Rights framework applies, the lethal attack on the drug smuggling boat—done without any judicial process—would be murder and a grave violation of international law. There was no self-defense at play here and the killing was done without judicial process.
The critical question, however, is whether that framework should apply. The second, and much older framework is the Law of Armed Conflict, takes a very different view of the use of lethal force. It recognizes that unless war itself is made absolutely illegal (which is not the case), a different set of rules must apply. In armed conflict, after all, we don’t (and can’t) have a judicial process before any use of lethal force by military forces. And it is simply unrealistic to make enemy armed forces off limits for attack simply because they are not at that time engaged in armed action.
This framework, therefore takes a different approach that distinguishes military action against combatants—those active in the hostilities—and civilians. A military force is allowed to use lethal force against combatants merely because of their status—not based on what they are doing (unless they are attempting to surrender, in which as lethal force is not allowed). To use an extreme example, this means that an attack on barracks filled with sleeping soldiers—who do not impose any risk at that time—would be lawful. Attacks on non-combatants (“civilians”) are not allowed, and even otherwise legitimate attacks on military targets can be unlawful if it causes disproportionate injury to civilians.
Under this framework, if the people killed on the boat are “combatants” engaged in an “armed conflict” with the U.S., they are legitimate targets for lethal force.
So this brings us back to the Martha Minow/Sesame Street test: which framework is the correct one to use? We have three things—armed conflict, normal law enforcement and the lethal attack on the drug smuggling boat. One of these things is not like the others. The key question is: which one?
I think the history of how the Law of Armed Conflict helps illuminate this issue. While the Law of War framework was developed in the context of state versus state military conflicts, it has been applied in other contexts as well. As a result of the rise of wars of liberation and civil wars in the 1950’s and 60’s, it was applied (with some variation) to wars against non-state actors. More recently—especially after September 11th—it has also been applied to attacks on terrorist groups when there was sufficient indicia of an armed conflict.
While you can certainly find a law professor here or there who takes the position the the Law of Armed Conflict does not apply to efforts to defeat terrorism—and that only law enforcement that complies with International Human Rights Law should be used—this is not a position adopted by the international community. As long as a terrorist group is engaged in “armed conflict” with a nation, the Law of Armed Conflict sets the ground rules. This is a position that even the International Red Cross accepts. This means that attacks of terrorist group combatants based on their status of combatants can occur without judicial process.
It is important to note, however, the application of the Law of Armed Conflict in operations against terrorist groups is subject to some important limits. First, there must be an “armed conflict” between the terrorist group and the nation taking action. While none of the treaties define this term, most military lawyers would accept that armed conflict requires a degree of violence of significant intensity and duration between a nation and an organized group. Isolated acts of violence—such as typical criminal behavior—is not enough. Second, even if the Law of Armed Conflict, applies, the rules still do not permit lethal attacks against non-combatants.
The Trump Administration appears to take the position that because Tren de Aragua has been designated a terrorist group, the Law of Armed Conflict applies to the attack on the boat. I think this argument fails for two reasons. First, even though Tren de Aragua is a criminal organization that is importing drugs into the U.S., they are far removed from the intensity of directed violence that meets the definition of “Armed Conflict.” It is a criminal organization focused on maximizing profit. Indeed, rather than engaging in a conflict with the US, it wants to avoid engaging altogether with the U.S. authorities It is in no way engaged with an intentional violent conflict with the U.S.
To hold otherwise would expand the scope of the Law of Armed Conflict—which, after all makes murder lawful—in very troubling ways. If the Law of Armed Conflict applies, it has implications that go far beyond this attack. Would this allow lethal strikes against the group within the U.S.? Would it justify an armed attack on Venezuela on the basis that Venezuela was harboring the group? Does it mean that captured Tren de Aragua members must be treated as prisoners of war rather than criminal defendants? Would members of group who murder benefit from the combatant immunity to prosecution established by the Law of Armed Conflict?
These are troubling questions. We need to remember that the Law of Armed Conflict was developed as a limited exception to International Human Rights Law, which prohibits state-sponsored murder. It is dangerous to expand its scope to longstanding criminal activity.
Second, even if the Law of Armed Conflict applies, it is not entirely clear that smugglers of drugs—who don’t appear to have any role in violent action against the U.S.—would qualify as combatants.
So one of these things is not like the other. In my view, the attack cannot be justified as within the framework of the Law of Armed Conflict, and must instead be judged by the International Human Rights Framework. We can certainly fight Tren de Aragua, but must do so—as we always have—using traditional tools of law enforcement.




I appreciate your analysis. Thank you. As an aside, I also liked Martha Minow very much. She was a tiny but mighty professor.
If International Human Rights law developed after the Law of Armed Conflict, how could the Law of Armed Conflict be developed as a limited exception to International Human Rights Law?