Trump's blockade of sanctioned Venezuelan oil raises new questions about legality

President Donald Trump’s blockade of sanctioned oil tankers off Venezuela’s coast is raising fresh questions about the legality of his broader campaign in Latin America and fueling concerns that Washington could be edging toward war. The administration says the blockade is narrowly tailored and not aimed at civilians, a justification it says aligns with its aim to cut off revenue streams linked to Nicolás Maduro. Critics counter that seizing oil tied to Maduro could provoke a military response from Venezuela and pull the United States into a high-stakes confrontation beyond the ongoing strikes against alleged drug-trafficking boats.

Rep. Jason Crow, a Colorado Democrat who fought in Iraq and Afghanistan, warned that the tactic could escalate into a broader conflict. “My biggest fear is this is exactly how wars start and how conflicts escalate out of control,” Crow said. “And there are no adults in the room with this administration, nor is there consultation with Congress. So I’m very worried.” Claire Finkelstein, a professor of national security law at the University of Pennsylvania, said the use of such an aggressive tool without congressional authority stretches the bounds of international law and increasingly looks like a veiled attempt to trigger a Venezuelan response. “The concern is that we are bootstrapping our way into armed conflict,” Finkelstein said. “We’re upping the ante in order to try to get them to engage in an act of aggression that would then justify an act of self-defense on our part.”

Trump has described the move as a “blockade” and has said it targets vessels facing U.S. economic penalties, but the tactic has drawn sharp rebukes from Democrats and, in some cases, guarded support from Republicans. Rep. Michael McCaul, R-Texas, said Trump going after sanctioned oil tankers linked to Venezuela is no different from targeting Iranian oil. “Just like with the Iranian shadow tankers, I have no problem with that,” McCaul said. “They’re circumventing sanctions.” The president has declared the United States is in “armed conflict” with drug cartels in an effort to curb drug flows to American communities. U.S. forces have attacked 28 alleged drug-smuggling boats and killed at least 104 people since early September, a pace that has heightened warnings of a potential broader war.

The campaign has drawn scrutiny in Congress, particularly after it emerged that U.S. forces killed two survivors of a boat attack in a follow-up strike. Yet Republicans have largely rejected calls for clearer congressional authorization for further regional action. Sen. Roger Wicker, Republican chairman of the Senate Armed Services Committee, said the entire operation is being conducted “on sound legal advice.” He has essentially ended his panel’s formal investigation into the Sept. 2 strike while defending the strategy as lawful.

The United States has a long history of naval pressure as a toll to compel behavior from rival governments, but in recent decades administrations have been cautious about maritime coercion that could punish civilians and be seen as an act of war outside of formal hostilities. During the 1962 Cuban Missile Crisis, President John F. Kennedy described his naval cordon to counter weapons shipments as a “quarantine,” a distinction many lawyers and scholars still emphasize in debates over Venezuela. Mark Nevitt, an Emory University law professor and former Navy judge advocate general, said there is a legal basis for boarding and seizing an already-sanctioned ship that is considered stateless or that claims two states, but that a blockade is a wartime operation designed to cut off access for a state as an enemy. “I think the blockade is predicated on a false legal pretense that we are at war with narcoterrorists,” Nevitt said. “This seems to be almost like a junior varsity blockade, where they’re trying to assert a wartime legal tool, but only doing it selectively.”

Geoffrey Corn, a Texas Tech law professor and former Army adviser on law-of-war issues, cautioned that the blockade may not foreclose other interpretations. He suggested it could be aimed at pressuring Maduro to concede power or to push his supporters away from the regime, rather than a clear bid to broaden conflict. “You can look at it through the lens of, is this an administration trying to create a pretext for a broader conflict?” Corn said. “Or you can look at it as part of an overall campaign of pressuring the Maduro regime to step aside.”

Nicolás Maduro Guerra, Maduro’s son and a lawmaker, denounced the measure and told the private sector to help shield the oil-dependent economy from disruption. “We value peace and dialogue, but the reality right now is that we are being threatened by the most powerful army in the world, and that’s not something to be taken lightly,” Maduro Guerra said.

Officials had offered little detail on how the blockade would be enforced, beyond a nod to maritime surveillance assets. The Navy reportedly has 11 ships operating in the region, supported by a broad array of aircraft able to monitor shipping routes into and out of Venezuela. While Trump’s rhetoric has leaned on the idea of a blockade, Pentagon officials say they prefer describing the action as a “quarantine.” A defense official, speaking on condition of anonymity to discuss internal deliberations, said a blockade, under international law, constitutes an act of war requiring formal declaration and enforcement against all inbound and outbound traffic. A quarantine, by contrast, is a targeted preventive measure aimed at illegal activity rather than a state’s entire economy.

The legal and policy ambiguities have surfaced in Congress. Rep. Adam Smith, the ranking Democrat on the House Armed Services Committee, said he was unsure of the blockade’s legality and needed lawyers’ input, adding: “They’re blockading apparently the oil industry, not the entire country. How does that change things? I gotta talk to some lawyers, but in general, a blockade is an act of war.” The debate comes as lawmakers weigh the proper scope of congressional authority over presidential uses of force in the region.

In historical terms, the United States has often used maritime pressure to coerce actions by other governments, but such tactics carry risks of civilian harm and international backlash. The Maduro regime’s reliance on a shadow fleet—falsely flagged tankers that smuggle oil to foreign markets—has been one of the main ways Caracas has tried to weather sanctions that began in 2005 and expanded to oil in subsequent years. PDVSA, the state-owned oil company, has been largely shut out of global markets, selling much of its crude at steep discounts through back channels. Maduro’s government insists it can weather any disruption to its oil sector, even as Maduro Guerra says the administration would cooperate with private sector partners to mitigate effects.

Analysts emphasize that the legal framework for the blockade remains unsettled, and the question of whether Congress has to authorize such actions is a point of ongoing contention. The administration argues the measure is limited in scope and designed to choke off illicit oil flows, while opponents warn that the approach risks drawing the United States into a larger, more dangerous confrontation with Venezuela. As the policy unfolds, the balance between enforcing tighter sanctions and avoiding civilian harm will be closely watched, both in regional capitals and in Washington.