Between the Trump administration’s war crimes rhetoric, its accidental and intentional targeting of civilians with military strikes, and its commencement of an unconstitutional and unlawful war of aggression, it is an understatement to say that it has demonstrated little respect for international law. But while these callous and careless acts dominate headlines and justly garner outrage and pushback, another destabilizing policy has gone largely unnoticed: The Trump administration’s apparent reliance on host state consent for deploying and using U.S. military force across Latin America.
Valid host state consent allows an outside state to intervene without violating the United Nations Charter’s prohibition on the use of force. But host state consent doesn’t address the question of whether peacetime law or the law of armed conflict applies, which in turn determines which actions are permitted. As I and my co-authors argued in Consent is Not Enough and in a prior Just Security article, the logic of the international legal order requires both the consenting and intervening state to independently evaluate whether there is an armed conflict before using otherwise impermissible lethal force. To do otherwise would expand an already-problematic legal loophole and undermine fundamental due process protections.
This is an increasingly pressing issue as the United States expands its military operations across Latin America. In March 2026, the United States announced that it was beginning joint operations with Ecuador against organized crime groups. Shortly thereafter, it stated that it had participated in a strike against a drug camp—which turned out to be a dairy farm. In May 2026, Guatemala agreed to a similar partnership (though, following initial reporting, Guatemala denied granting the United States permission to conduct strikes on its soil). In June 2026, President Trump celebrated a U.S. and Venezuelan joint operation that killed Héctor Rusthenford Guerrero Flores, the leader of transnational criminal gang Tren de Aragua. (Though there is some question about the validity of Venezuelan consent for this strike, given the U.S. removal of its head of state and President Trump’s “We’re in charge” pronouncement.) The U.S. Department of Defense also reportedly intends to pressure Honduras and Mexico to give consent to U.S. force deployment, with the aim of enabling “U.S. boots on the ground and drone strikes” as part of a broader strategy to “normalize an American military presence.” The United States has claimed that it is in an armed conflict with some of these entities, but there is little factual support for this assertion. It also has suggested that it is acting in concert with the host states, providing an alternative justification for its military actions.
If based only on valid host state consent, however, U.S. military strikes in Latin America are probably unlawful. As discussed below, like the military strikes on boats in the Caribbean Sea and the eastern Pacific Ocean, these actions appear to be occurring outside of an armed conflict. The targets may be criminals; they do not appear to be combatants. And, if they are merely criminals, the strikes are unlawful—a host state cannot invite another one to kill one of its citizens. As former State Department lawyer Brian Finucane, observed, “depending on the facts, further attacks could amount to premeditated killings outside of armed conflict, which some of us lawyers would refer to as murder.”
Whether or not targeting an individual is “murder” depends in part on whether a domestic situation is an internal disturbance or an armed conflict. As articulated in the U.S. Law of War Manual and other sources, a non-international armed conflict exists when a two-pronged threshold test is satisfied: a state must be fighting an armed and sufficiently organized non-state actor and the violence must meet a certain level of intensity. The first prong requires more than criminal gang activity; the group must have a command structure and be engaged in organized violence against the state. The second prong requires more than sporadic acts of criminal violence; there must be significant and protracted military operations.
If the threshold test is not satisfied, both the host and intervening state are governed by peacetime law, which includes the host state’s domestic laws and both states’ human rights obligations. With regard to domestic law, Ashley Deeks has suggested that the intervening state should be subject to a “duty to inquire” to determine if the “host state’s consent exceeds the scope of the host state’s legal authority.” There is some debate over the extent to which human rights obligations apply extraterritorially, which might appear to free the intervening state to engage in actions abroad it could not take at home. However, an intervening state’s actions taken pursuant to host state consent must comply with the host state’s human rights obligations towards its citizens. For example, human rights law limits the amount and kind of force that can be used in law enforcement operations. Lethal force may only be used as a “last resort only permissible where necessary to counter an imminent or grave threat to life or physical integrity . . . and when less violent means are not or would not be effective.” Unless there is an imminent threat of death or grievous injury—a necessary factor that does not appear to be satisfied in the Flores killing—using military force to target even the most powerful criminal is prohibited.
If the threshold test for an armed conflict is met, the law of armed conflict applies, establishing certain requirements and relaxing others. Lethal force is permissible, provided that each individual attack in an operation complies with the international law governing the conduct of hostilities. This includes the obligations to distinguish between civilians and combatants, to not engage in disproportionate strikes where the collateral damage would be excessive when compared with the anticipated military objective, and to take constant care and all feasible precautions to minimize harm to civilians.
Regardless of the state of domestic upheaval and applicable legal regime, states can request help in responding to internal threats; what changes are the requirements for how host and intervening states can respond. Host states cannot ask others to do what they cannot do themselves, and an intervening state cannot treat host state consent as a blank check for military action.
Granted, which law governs U.S. actions in Latin America requires a fact-specific and contextual evaluation, and we don’t have all the facts. The conflicts with the various drug cartels and criminal organizations may well satisfy both requirements, but there is no evidence that anyone in the administration is conducting this analysis. Instead, as noted by multiple authors, the Trump administration has provided no information suggesting that the “organization” or “intensity” thresholds have been met with regard to any of the criminal gangs it is engaging in Ecuador, Guatemala, Venezuela, or elsewhere. Further, even if there was a facts-based determination that an armed conflict exists in one state—say, in Ecuador, where thousands have died in drug gang-related violence—such an assessment would not automatically apply to the rest of Latin America.
The armed conflict threshold test exists to prevent civilians from being treated—and killed—like combatants. States should not be able to consent to others using force that they cannot use themselves, intervening states should not blindly rely on host state consent when conducting military strikes, and intervening states certainly cannot demand that host states consent to acts that neither state can take independently.
Instead, both host and intervening states have an obligation to independently evaluate whether an armed conflict exists, determine what legal regime applies, and act accordingly. If the United States is targeting individuals outside of an armed conflict, it is violating both domestic and international law that prohibit extrajudicial state-sponsored killings. Substituting consent for the threshold test doesn’t just distort international law—it strips individuals of legal protections that prevent summary executions.
