This post is part of a symposium on international law under the second Trump administration. Read the rest of the posts here.
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It was morning on Easter Sunday when I started to think about nuclear war. “Open the Fuckin’ Strait, you crazy bastards,” the U.S. president railed on TruthSocial, addressing the Iranian government, “or you’ll be living in Hell.” A couple days later, he followed up: “A whole civilization will die tonight.” These threats later proved to be characteristic bluster. But, at the time, a tragic escalation of an already immoral and illegal war seemed far from implausible.
It is clarifying that the United States would issue such apocalyptic threats over what was effectively an issue of maritime trade. That countries might go to war over commercial interests is hardly surprising. The history of international law and politics is riven with such wars. But, for much of the past century, international lawyers have sought to drive a wedge between “economic” matters and the use of military force. The first months of 2026 suggest that wedge is no longer viable.
If there is a new international legal order arising out of the present moment, we can see it on the high seas. On the oceans, the standard lines—between war and peace, economic coercion and military force—dissolve. At sea, as Laleh Khalili observes, violence and commerce always travel together.
SWAT in the Caribbean
In a video released by the Department of Justice in early December 2025, U.S. troops rappel from a helicopter onto the Skipper, an oil tanker bound for Venezuela. They fan out across the deck, weapons drawn.
The troops are part of an “elite” Coast Guard unit called the Maritime Security Response Team. Created after the attacks of September 11, 2001, as “a highly specialized resource with advanced counterterrorism skills and tactics,” these units operate like a high-seas military SWAT team.
After about forty-five seconds of video, one of the helicopters departs. The tanker is under U.S. control now. The vessel and its cargo, seized at gunpoint, is subject to a pending forfeiture action in U.S. courts.
On CNN, as the video plays on loop, a former U.S. intelligence official tells viewers not to worry. The U.S. military was merely executing a search warrant, enforcing U.S. sanctions laws. “In the past, everybody has wanted to pick up these kinds of tankers, but we haven’t had the assets in the region to do it,” the former official says, with a levelheaded seriousness. “We now have twenty percent of our deployed naval vessels … in this very small body of water.”
Of course, not just anybody can seize a tanker on the open ocean. Ships on the high seas are generally subject to the jurisdiction of their flag state. Other states’ militaries can exercise a “right of visit” upon a foreign-flagged vessel only in extremely limited circumstances—circumstances that do not, absent UN Security Council authorization, include sanctions enforcement. Carrying out a military operation aboard a foreign-flagged vessel on the high seas also runs afoul of the core prohibition on the threat or use of force in the United Nations Charter.
Still, through a bricolage of national and international legal materials, the United States has managed to assemble a plausible justification for these actions. First, using domestic emergency powers, the United States places a vessel on any one of its many sanctions lists. These unilateral sanctions, by definition, lack UN backing. But the United States (plausibly) maintains that such unilateral coercive measures are permitted by international law, notwithstanding efforts by generations of scholars and diplomats to articulate broad legal prohibitions on economic coercion. Second, the vessel must be rendered stateless, thus making it lawful to board the ship. This can be done by pressuring flag-of-convenience states to expunge sanctioned vessels from their registries. And, third, once boarded, the United States applies civil asset forfeiture law to seize and sell the sanctioned vessel’s cargo. This last step relies on a broad understanding of the boarding state’s rights, under international law, to assert its own jurisdiction after boarding a stateless vessel. And, in applying its own law, the United States effectively leverages the same mechanism notoriously used in domestic proceedings to immiserate ordinary people charged with crimes.
In this way, the United States can stitch together something that looks very much like a naval blockade—which, by international consensus, would be an act of aggression—using domestic emergency powers and ordinary law-enforcement tools. It then projects that quasi-blockade into the fissures in the contemporary international legal order.
These actions give the lie to the idea that sanctions are peaceful or, as the World Court once put it, take place only on the “economic plane.” Sanctions enthusiasts have long trumpeted sanctions as a non-violent alternative to war. In 2015, President Obama celebrated the Iran Nuclear Deal—achieved after sustained sanctions pressure—as having been won “without firing a shot.”
The footage of the Skipper incident makes clear that the line separating economic and kinetic warfare is neither so firm nor so certain. The seizure of the vessel—and others afterward—was made possible by a massive military buildup. This buildup has accompanied a U.S. “murder spree” against civilians in the Caribbean, and it led to the unlawful U.S. invasion of Venezuela. And sanctions enforcement itself is conducted at gunpoint.
The Toll Booth
Four months later, rendered in a satellite’s-eye view, the Strait of Hormuz looks like a curve in a Formula 1 circuit. It’s been about twenty-four hours since a cease-fire brokered between the United States, Israel, and Iran was supposed to allow safe passage through the strait. The digitally rendered map shows ships—represented by green or red dots—still clustered on either side of the strait. Despite the cease-fire, almost none are moving.
Those few dots that make the transit hew closely to Iran’s coast. They’re taking the “so-called ‘toll booth’ route,” where Iran is charging for safe passage. To avoid U.S. sanctions, payments are made either in yuan or cryptocurrency.
This time, the media tells us to worry. Iran’s toll-booth system violates customary international law principles of free navigation. “Iran is not allowed to introduce tolls,” says the U.K. foreign secretary. “No country should be able to hijack” international shipping routes.
Iran would, of course, beg to differ, and not just because of the illegal war prosecuted upon it by the United States and Israel. Iran, like the United States, is not party to the UN Convention on the Law of the Sea. And, again like the United States, Iran likes to pick and choose the aspects of that Convention it believes reflect customary international law. Given the strategic importance of the strait, Iran has maintained that the right of transit passage afforded by that treaty is not binding upon it.
In taking this position, Iran is certainly an outlier. But the international legal system is no stranger to outliers. Indeed, the United States’ own aggressive enforcement of unilateral economic sanctions relies on legal arguments that even many U.S. allies would not endorse. Even so, with its immense leverage over financial chokepoints, the United States has been able to convert those contested-but-plausible legal arguments into a form of de facto global regulation, which is just as likely to compete with public international law as complement it. What Iran might be able to do with its leverage over the strait remains to be seen.
When asked about Iran’s plans to charge for transit through the strait, President Trump initially showed none of the compunctions of his British counterparts. “We’re thinking of doing it as a joint venture,” he told a reporter. “It’s a beautiful thing.” Days later, however, the President was back to threatening a full-blown naval blockade of the strait, saying: “No one who pays an illegal toll will have safe passage on the high seas.” As of this writing, the United States now purports to maintain a formal wartime blockade of Iranian ports alongside peacetime sanctions enforcement efforts, resulting in a tangle of coercive measures that proves difficult for even experts to parse.
Imperial Orders, Past and Future
A comparison between these two scenes presents, in dramatic fashion, the profound asymmetries of today’s international economic order. Over the course of the twentieth century, a series of hard-fought political and legal battles liberalized trade, secured freedom of navigation, dismantled capital controls, protected foreign investment, and established binding and enforceable mechanisms of commercial dispute settlement. The transit passage of commercial shipping through international straits—a principle which President Trump recently rendered in all caps as “ALL BEING ALLOWED TO GO IN, ALL BEING ALLOWED TO GO OUT”—is a piece of this liberal economic order.
This order was, of course, always asymmetrically liberalized. The post-colonial economic order, born into the world of the UN Charter’s principles of sovereign equality and non-intervention, was nonetheless “saturated” with economic coercion. Financial sanctions, whereby U.S. Treasury officials can effectively reorder the circulation of goods and capital at the push of a button, are only the sharpest edge of that coercion.
And we like to forget just how sharp that edge really is. Sanctions, whether public or private, are always enforced by some mixture of social pressure, economic control, and physical violence. Over the past quarter-century, the United States has been experimenting with increasingly transnational, coercive, and carceral methods for enforcing its sanctions. Both the Biden and first Trump administrations evolved the techniques now being used to enforce the quasi-blockades against sanctioned vessels. Financial sanctions may not lead inexorably to war, as some of our forebears would have predicted. But violence—whether structural or physical—is always present.
Now, on the high seas, we may be seeing the death of one of the liberal order’s central myths. It does no good to insist that sanctions are peaceful alternatives to war when they are the legal pretext for the construction of a quasi-blockade. It seems increasingly senseless to insist on a hard-and-fast distinction between military force and economic coercion, when the latter is enforced at the end of a gun. And, if it remains tied to this distinction, the international legal order may soon find itself dragged beneath the waves of economic and military conflict.
