Can Denmark Use International Law to Fight Russia’s Shadow Fleet?

Small European states, such as Denmark, face daily the threat of an environmental Armageddon, as dozens of decrepit, single-hulled, barely insured Russian oil tankers wend their way through the narrowest of straits to the open seas. Often they don’t even have local pilots to help them navigate the treacherous waters, let alone proper paperwork, further raising the consequences of a disastrous oil spill.

What makes this traffic especially galling is that it is done illegally, in circumvention of near-universal sanctions, and in service of a criminal state whose oil exports serve to underwrite the extermination of a neighboring country. The United States and, most recently, the United Kingdom have sanctioned a handful of those tankers, but the trade continues. On paper, coastal states could—and might yet—take action to stop that trade. In practice, Russia is a very big country that brandishes nuclear threats with abandon.

“The question is, what risk does that traffic pose? As a person living just down the hill from the strait, that of course poses an environmental risk if we have a problem,” said Kristina Siig, a Danish resident of the straits, and, as it happens, an expert on maritime law.

What’s a state to do? On the one hand, international law gives coastal states the right to take action against ships that pose grave environmental risks, as the rusting Russian shadow fleet almost certainly does. There are several explicit articles in the 1982 U.N. Convention on the Law of the Sea (UNCLOS)—the global constitution of maritime law—that seem to offer coastal states a way to curb shipping that poses a serious risk to the environment.

On the other hand, commercial traffic through the Danish straits is sacrosanct under international law. If UNCLOS isn’t clear enough on that point, lawyers will happily point you to the 1857 Copenhagen Convention that guarantees the right of innocent passage through the Danish straits for commercial ships.

The big problem is that Russian oil exports are not, in layman’s terms if not legalese, “innocent passage.” They are outlaw ships doing outlaw business and carrying dangerous cargo to boot. International law, and maritime law in particular, is rich in verbiage and caveats. What it is often short of, in Western eyes and practice, is common sense. Now, some countries are looking to take a more proactive approach to turn the letter of the law into a way to bring the lawless to heel.

In June, Danish Foreign Minister Lars Lokke Rasmussen said that Denmark and some other Western countries are exploring ways to limit, if not entirely stop, the dangerous traffic of Russia’s shadow fleet through the one exit from the Baltic Sea, specifically by invoking some form of coastal state rights to prevent environmental harms. Parallel plans reportedly under development include ways to partially limit the unfettered passage of ships that don’t comply with international maritime regulations, from ship safety to oil-spill insurance; other plans would use the sanctioning power of the U.S. Treasury to put teeth in shadow fleet enforcement.

With local plans yet to fully materialize, Denmark did feel emboldened in late summer to put an end to Russian ships getting port service on their way out of the straits, backed by the latest European Union sanctions package that allowed those restrictions.

And the United Kingdom in July announced a “call to action,” endorsed by 43 other states and the EU, that would use stricter enforcement of International Maritime Organization rules to check the shadow fleet’s depredations. Specifically, Britain wants “flag states,” the countries that officially register a ship and are responsible for its operation, to clean up their act and enforce safety and insurance rules. And it wants port states to crack down on illegal transfers of cargoes and dodgy insurance practices that deliberately evade the near-universal adherence to maritime norms.

“There is no doubt that Russia is flagrantly breaking the law, so if the allies are working together to ratchet up the legal response, that is entirely understandable,” said Harold Koh, a professor at Yale Law School and a former legal advisor to the U.S. State Department.

But it’s not clear that even the black letter of maritime law that gives coastal states rights against environmental threats would be enough to curtail Russia’s shadow fleet, said Siig, who is a professor of maritime law at the University of Southern Denmark. Forcing compliance with insurance rules, for instance, could add burdens to Russia’s makeshift fleet but likely wouldn’t stop it. And any effort to plug the straits would run into equally valid legal protections, long defended by Denmark, of free passage through those very same waters.

“I see this as more of a diplomatic problem than a strict legal problem,” she said. “If you want to stop Russian oil from coming through the straits, forget it.”

Legal fig leaves aside, Russia would not be happy.

“This would be a legal charade, and seen as such,” said Sergey Vakulenko, an energy expert at the Carnegie Russia Eurasia Center and a former Russian oil executive. He said even a legalistic effort to restrict traffic through the straits would undermine international law and potentially be seen as a blockade—a potential act of war—by Russia.

Or as Siig puts it: Even if Denmark and some allies were to muster the legal arguments to go after that illicit trade, Russia remains as physically close as it was during the atomic-frightened years of the Cold War.

“If you are going to poke a bear, do it with a very long stick,” she said.

The search for legal remedies to bad actors isn’t limited to shadow fleets, or even to Russia. The International Criminal Court (ICC) has issued arrest warrants for Russian President Vladimir Putin and others for some war crimes already; the West has tied itself in knots to justify first the freeze, and now a partial seizure, of Russia’s huge overseas central bank reserves. The Philippines took China to court over its maritime depredations years ago and won handily.

But maritime law is such an important battlefield because the seas and oceans are so central to the modern world.

Take the undersea cables and pipelines that form the central nervous system of the global economy. That sprawling infrastructure is a particular target for Russia, which when not attacking those structures directly or indirectly is mapping them out for the future. NATO, the CIA, MI6, and others are growing more concerned by the day about the vulnerability of European infrastructure in particular to Russian sabotage.

But the 40-year-old constitution of the sea has little to say about protecting now-vital assets. The only parties that have jurisdiction if something goes wrong—if a Chinese ship damages a crucial energy pipeline between two European states, say—are the wrongdoers themselves; coastal states have no clear legal remedies as yet. The flag state that is legally responsible for a ship, whether a true maritime nation like the United Kingdom or a black-flag state for rent like Gabon, is the one with jurisdiction over such incidents.

International legal experts have spent years trying to update the dated provisions on UNCLOS, which has plenty to say about the environment, to create a new regime that will address broader concerns about protecting vital maritime areas. Other suggestions include a more expansive definition of the UNCLOS term “marine environment” to protect against more than just pollution. But although that might work to cover damaged oil pipelines, it would hardly apply to severed data cables.

Legal scholars are working to identify what kind of tools, from existing provisions of UNCLOS to the rules about self-defense from attack, might apply to protect those assets from the kind of hybrid warfare that is now endemic upon, and under, the seas.

“The Law of the Sea Convention did not foresee such a manipulation of the law, and outright sabotage of objects of critical infrastructure, such as submarine cables and pipelines,” said Alexander Lott of the Norwegian Centre for the Law of the Sea at the Arctic University of Norway, who literally wrote the book on maritime law and hybrid warfare.

With formal updates to the sprawling UNCLOS unlikely—the massive treaty took a decade to finish its third negotiation and become law, and further amendments now would be a legal morass—one alternative might be new customary law, rather than a revised treaty.

Denmark itself stretched legal imagination to create exclusion zones around the damaged Nord Stream pipeline in the Baltic. New customary law could gain legal force, said Jacques Hartmann, an international law expert at the University of Dundee and a former legal advisor to the Danish Foreign Ministry, “if enough states came out and said, ‘Subsea infrastructure is part of our national security.’ Whether or not there is the political will to do so is less clear.”

Other scholars reach for different potential legal remedies for what is, essentially, piratical behavior. For centuries, states have known how to combat piracy, even if they have often had trouble defining just what a pirate is at any given time. The British Admiralty historically embraced expansive definitions of piracy and its national prerogatives to protect what it saw as its vital maritime interests, noted Daniel Skeffington in the Naval Review. Some scholars are starting to suggest that an updated definition of piracy might be a way to combat severed cables (if not severed thumbs), as the United States sought to do back in the 19th century to protect telegraph lines.

The piracy provisions of international maritime law, said Hartmann, were “drafted at a time when piracy was a historical crime.” But piracy evolved in the very years UNCLOS was drafted and even after. The international community found another way to codify action against air pirates and later more traditional maritime pirates; many of those same international understandings underpinned the global fight against terrorism, which he suggested is a useful template for understanding and combating the new type of threat.

“Every once in a while, it becomes clear having a free-for-all area of lawlessness is not that useful,” Hartmann said.

But if it is hard to even define the kind of gray-zone tactics increasingly used by states like Russia, it is even harder to pinpoint ironclad legal remedies. That doesn’t mean it’s not worth trying.

“Hybrid warfare tends to target the gray zones of the legal system. It is reliant on the very indeterminacies rooted in the law, so there is no silver bullet to fight it,” Lott said. “But victims need to be more assertive in enforcing their laws,” even if there is not a single “specific and crystal-clear legal basis for any particular action they might take.”

The reticence with which Western states approach the possible weaponization of international law is deep-rooted. International law was conceived in Latin and is practiced in English. Western states by and large seek to uphold the girders of the international system they built and from which they benefit (except when pointedly attacking bits of it, such as the ICC, or refusing to join its biggest groupings altogether, such as UNCLOS).

Big revisionist states don’t have those reservations. Russia has trampled not only the spirit of international law but the letter as well, not just with shadow fleets and sabotage, or war crimes various; when scholars point to piratical behavior and talk about taking a gloves-off approach to wrongdoers at sea, they often cite Russia’s own illegal actions, such as the 2018 detention of Ukrainian sailors in the Black Sea before the latest war even began.

China’s Foreign Ministry explicitly makes the weaponization of international law to advance Beijing’s interests a centerpiece of its foreign policy, continuing a centurylong legal tradition meant to undo “unequal treaties” by turning the West’s preferred tool against it. That explains much of China’s legally baseless and indisputably dangerous behavior over the last decade-plus in waters such as the South China Sea. (China’s own vision of a modern navy includes a very muscular approach to maritime law and ocean governance.)

When it comes to specific remedies for specific problems, such as plugging the one exit Russia’s illicit oil fleet has from the closed waters of the Baltic, those philosophical constraints end up hamstringing policy. Denmark and other coastal states are leery about actively using even defensible chapter and verse of international law to protect their coasts not just out of fear of Russian reprisals, but because undermining even one brick of the edifice of international law could boomerang.

“Freedom of navigation, and the whole of maritime commerce, is reliant on the straits regime” that allows free passage, Lott said. “If they were to do anything to clearly violate the regime, then they would essentially shoot themselves in the foot and provide arguments for other states that might not be interested in freedom of navigation, and this would create a tremendous headache for Western states. This is what explains the hesitant behavior.”

But that is what makes the nascent green shoots of Western weaponization of law to combat particular bad actors so encouraging. Seen as less a straitjacket than a ripcord, international law, properly applied and politically supported, could go some way toward turning the black letter of the law into a useful tool to chase black flags from the sea.

“The trick is to find the more nuanced approach,” Lott concluded, “to use legal measures without undermining the legal principles.”