NATO Wants to Boost Its Undersea Defenses

There are just two cables linking the remote Arctic archipelago of Svalbard with mainland Norway, providing almost all the data from polar-orbiting satellites to the rest of the world. And two years ago, they nearly stopped working.

Norwegian police images released in late May show the catastrophic damage done to one of the Svalbard fiber optic cables: the plastic casing slashed open, the cable exposed, and wires unfurled like a faulty electrical cord.

The unsolved January 2022 incident, which cut data flow from the SvalSat satellites and limited air traffic to the archipelago, is serving as a cautionary tale about what can happen when undersea cables—which underpin most of the global communications network—are cut. Yemen’s Iran-backed Houthi rebels did just that earlier this year when they targeted a key bottleneck between Asia, Africa, and Europe—after threatening to do so in response to Israel’s war against Hamas in Gaza.

The threat is not just limited to one or two areas. NATO officials believe that Russia has a decadeslong program to map out European undersea infrastructure as part of an effort to prepare the battlefield for a possible conflict with the 32-nation alliance.

“We know the potential is there to do damage if they would want to,” said a senior NATO official, speaking with Foreign Policy on condition of anonymity based on ground rules for interacting with journalists set by the alliance. “Part of Russian war planning is knowing where the critical infrastructure of your enemy is.”

It doesn’t take a huge effort by the Russians to get the information that they need to cause harm. Most of the pipelines are run by utility companies, and much of the data on where the cables run is in the public domain because of licensing requirements.

In response, NATO now has an undersea infrastructure coordination group that brings together military and civilian officials and has the power to convene top representatives from the private sector, based out of the alliance’s Maritime Command in the London suburb of Northwood.

“The question is connecting all the dots and creating a network,” the senior NATO official said of the information and intelligence exchange.

The ambitious effort is an attempt to use computing power to protect the vast undersea cable network that undergirds much of the global economy. Since it’s nearly impossible to patrol undersea all the time without an unrealistic number of submarines—especially across the Atlantic Ocean—the alliance has to rely on computers. Drawing on data from software interfaces and the cable and pipeline operators themselves, NATO allies are working together with the private sector to create a massive alert system for the thousands of miles of undersea infrastructure in Northern Europe, relying on sensors from the cables as well as acoustic sensors attached to wind turbines, which can be used to detect irregularities.

“NATO processes, I think, are sort of in a very early phase,” said Audun Halvorsen, the director of the emergency department for the Norwegian Shipowners’ Association (and formerly the country’s deputy foreign minister). “They are basically trying to map out the landscape when it comes to jurisdictions, when it comes to authorities involved. You are facing a huge range of different regulatory regimes for the industry around the undersea basin.”

The strategy of cutting undersea cables is almost as old as modern warfare. (The first trans-Atlantic cables had been laid a few decades earlier, in 1866.) Britain began cutting German undersea cables at the outset of World War I to sabotage communications—and the Germans happily returned the favor. When submarine telephone cables began being laid in the 1950s, during the early days of the Cold War, Soviet trawlers damaged underwater cables near the Newfoundland coast. The U.S. Navy alone owns more than 40,000 nautical miles of active cables on the seafloor.

But with fiber optic cables becoming the ubiquitous plumbing that underpins global communications and trade in the internet age, the vulnerability in the seabed is growing. Norway’s undersea pipeline network provides about 40 percent of Europe’s natural gas supply, with pipelines crisscrossing the North Sea to the United Kingdom and the rest of the continent along with about 500 underwater communication cables that carry roughly 97 percent of the world’s internet traffic—some of them extending all the way across the Atlantic Ocean. That’s as much as $10 trillion in financial transactions every day.

“It is less kinetic and more a way for the Russians to show the West that ‘we know you guys are quite challenged in securing that infrastructure,’” said Sebastian Bruns, a naval expert at the Center for Maritime Strategy and Security at the Institute for Security Policy at Kiel University in Germany. “They would be tackling the very seams of what ties our societies together.”

About 100 of those cables break globally every year—most by accident—and it’s basically impossible to protect all of that infrastructure, other than by adding even more redundant data cables or ensuring that more liquified natural gas tankers are waiting out at sea, providing another source of gas if there’s a break.

The concern for that infrastructure has led to the NATO effort, which began after the September 2022 attacks on the Nord Stream 1 and 2 pipelines that transport natural gas from Russia to Germany. Even though much of the data about where the cables are located is public, the sensor data that could determine whether a linkage is in danger of being cut is stovepiped far under the national level—meaning that it’s kept within the companies themselves. The United States alone has 85 licensed undersea telecommunications landing stations. And while many pipeline owners have taken into account the risk of corrosion and possible accidents, factoring for sabotage is less common.

Some experts believe that smaller groups of countries can move faster than NATO to protect the cables. In April, Norway and five other countries bordering the North Sea—Belgium, Denmark, the Netherlands, Germany, and the United Kingdom—agreed to share operational information to protect undersea cables and pipelines against sabotage. And the Council of the Baltic States recently met in Finland to condemn Russia’s hybrid tactics—incidents of sabotage that fall beneath the level of declared war, including threats to undersea cables.

Already, Russia is lashing out at Nordic countries through other means. Since Finland joined NATO in April 2023, Russia has been sending waves of forced migrants to their 830-mile-long shared border—nearly half of the entire boundary between Russia and the alliance—forcing Helsinki to shut down all of its crossings. Russia has proposed redrawing borders in the Baltic Sea, hit Sweden with cyberattacks, and even removed buoys on the Narva River that Estonia put in place to mark their maritime frontier.

“All of our economy under the sea is under threat,” Vice-Adm. Didier Maleterre, the deputy commander of the NATO maritime command, said in April.

The threat is heightened by a Russian submarine program that has resurged since the 2022 invasion of Ukraine, operating from the Kola Peninsula. But problems can also be caused by unintended anchor drag from commercial ships. The Hong Kong-flagged and Chinese-operated NewNew Polar Bear, suspected of damaging the Balticconnector gas pipeline between Finland and Estonia in October 2023, sailed away along the Northern Sea route with protection from a Russian icebreaker.

In the face of all the other challenges—shrinking navies, a resurgence in piracy, the Red Sea attacks—that undersea flank is exposed.

And officials say that Russia’s use of criminal and civilian networks—which are also deployed to create influence networks in mainland Europe—makes all of these tactics, including the sabotage of undersea pipelines, extremely difficult to pin on the Kremlin. The Russian surveys of the Baltic seabed, for instance, are carried out by ships with an ostensibly scientific purpose.

“We are still tied into this military-versus-civilian division of labor, whereas the Russians are much smarter using civilian vessels for military purposes,” said Bruns, the naval expert. “We are yet to find a solution for that.”

Scientists still understand relatively little about the form of the seafloor. So artificial intelligence is also being used to map it, providing another potential method to spot would-be Russian cable snappers. Some NATO countries and operators are even thinking about burying their pipelines in the seafloor, especially in the Baltic Sea, where the average depth is just under 200 feet. It’s already standard practice near most European coastlines, since it helps protect against bottom trawlers and ship anchors.

After the Balticconnector pipeline incident last fall, Norway began to do an inventory of its own undersea infrastructure, starting with oil and gas before branching out to map parts of the electrical grid and communications cables that ran underwater. Authorities were able to search nearly 5,600 miles of oil and gas pipelines.

“We searched everything,” said Gen. Eirik Kristoffersen, Norway’s chief of defense. “When we found something, we used our military experts to look [at], ‘what is this? Is this something that has been placed there? Is this something from World War II? Is it something that the fishermen dropped?’”

The ability to conduct such an extensive search stems from the infrastructure of the private sector. Norway’s energy industry already has preparedness mechanisms in place to help protect and repair undersea infrastructure for pipelines and electric cables, Halvorsen said, which is coordinated by Norwegian operator Equinor. It’s a model that Halvorsen believes has promise for communication cables, too. But across most of NATO, that capability is limited.

“There is basically zero capability in government hands to survey, repair, maintain, [or] replace any of this infrastructure,” Halvorsen said. “All that capability and capacity is for the civilian industry. So to protect this kind of underwater infrastructure, you need to have some kind of functioning interface between the government side … and the industry.”