Hybride war on the seabed

This article was written as a result of the sabotage against the Nord Stream gas pipelines in September 2022. In a modified form, it will be published in the Tidskrift i Sjöväsendet No 4, 2022.

The sea is at once a road, a source of wealth and an area for the exercise of power.
The underwater explosions of Nord Stream 1 and 2 on September 26 have put the underwater domain on the Swedish political map.
According to the US maritime strategy Advantages at Sea, the seabed is a subset of the underwater domain, which in turn is part of the maritime domain. This extends from the seabed to space including the cyber domain. This article is a first attempt to discuss what war on the seabed - Seabed Warfare - is or can be.

In an interview for the Swedish NGO Folk och Försvar [People and Defence] the 6th September, 2022 I said:

"The explosions have required relatively large charges - several hundred kilos. No "amateurs" can work at a depth of around 100 meters with such large charges. The major powers – especially Russia – have good capabilities in this area. But the technology is widespread. The offshore companies can work at a depth of several thousand meters (at least down to 3,000 meters). The charges must have been placed before the explosions - perhaps long before they detonated. They must have been placed by a manned or unmanned underwater vehicle. This may have been "based" on a submarine or surface vessel. None of this is technically strange. The ongoing investigations will hopefully provide answers to some questions".
“Given the technical conditions, terrorist organizations can be directly ruled out. The US has been mentioned as an actor, but what would be the motive? A "false flag" operation? Possible? Likely? Not particularly. Russia is the most likely culprit. Russia has declared war on the West. By attacking an unused gas pipeline, they have shown that they can - most people understand the signal: "if we want, we can blow up your gas pipelines (and others) with consequent problems for your populations this winter." But it also creates confusion and doubt in the West - which is one of the main goals of hybrid warfare. Something that succeeded. The gas pipelines have been declared by Russia to be of vital strategic interest. The sabotage can therefore be a pretext for a strengthened and aggressive naval presence around the command. In turn, this can lead to demands for control of maritime traffic in the area. In that case, it can be assumed that the Russian ships would "find" evidence of terrorism, etc. The whole thing could become extremely unpleasant for us.”
By the time this is read, most of the above may have been proven wrong. But it is not exactly these explosions that the article is about either - they are just the reason.

The seabed as a part of the underwater domain
In the past, the importance of the underwater domain was primarily linked to naval warfare: reconnaissance, attack and defense of surface vessels (submarine, mines), attack against land targets (cruise robot), and for the major navies, strategic deterrence with ballistic nuclear weapons.
In recent years, the maritime infrastructure at sea has received increasing attention from a strategic point of view. However, this connection is not entirely new. The first working submarine telegraph cable was laid in 1866 and the first attack took place in 1898 when the US cut the cable to Cuba. As early as 1917, the first "hacker attack" occurred when the Allies managed to gain access to the so-called Zimmerman telegram from a cable from Mexico to Germany; this telegram, as is well known, became a reason for the United States to enter the First World War.
A more modern example is the cutting of an important data-cable, between mainland Norway and Svalbard, a month before the Russian invasion of Ukraine, the 24th of February, 2022. 
During the Cold War, the United States deployed extensive reconnaissance systems to track Soviet submarines (Sound Surveillance System, SOSUS). During the 70s, the USA developed a mine, the Mk60 Captor, with a torpedo as an effective part for great depths.
Today, the underwater domain is gaining more and more economic weight, which does not mean, however, that communications at sea have become less important. Sweden, as well as Europe, is to  80-90% dependent on maritime transport. Fishing is still vital - 1.5 billion people get their main protein supply from the sea. In addition, the sea itself contains substances and organisms that are of decisive importance for the climate and of growing importance for the biochemical and pharmacological industry. These factors, which are part of the reason why the maritime domain is increasingly at the center of global geopolitical developments, are not discussed further here. Instead, we will concentrate on the underwater domain and especially the seabed.
The underwater domain can be divided into a number of different layers. The first limit is 200 m, further down the light does not reach. The deep ocean starts at 3,000 feet - 900 meters - approximate maximum limit for conventional submarine operations. The deepest boreholes for oil and gas are at 3,500 m. 97% of the sea is above 6,000 m depth. The Mariana Trench is the deepest at 11,034 meters. Perhaps 20% of the seabed has been mapped. We still know little about the organisms that live at the really great depths; how can they perceive the surroundings? How do they manage to live in the enormous pressures?

Minerals, oil and gas

On and in the seabed there are great riches in the form of. e.g., earth metals, necessary for the electronics industry. Seabed mining may soon be a reality, which, certainly, drive the technological development regarding work on great depths. Outside the continental shelf, mining is regulated by the International Seabed Authority, which, hardly, will attenuate possible conflicts.

A large part (30%) of the world's supply of gas and oil comes from offshore platforms. Their number varies with the economy: between 15,000 and 20,000. These are "inhabited" by several hundred thousand people. In the future, platform work will increasingly be automated and moved down to the seabed.
Operationally, the platforms can be compared to small islands – an oil or gas field can thus be compared to an artificial archipelago. During the Iran–Iraq War (1980–88), the Iranian Revolutionary Guards used the platforms as bases for their Boghammar boats, leading to Operation Praying Mantis in 1988, when the US Navy attacked these.
As for gas, now in the centre for geopolitical interest, the most interesting, there are now two options. Either the gas goes through a pipeline to a central plant on land or is converted at high pressure into liquid form by an FLNG – Floating Liquified Natural Gas – and then transported further by an LNG tanker. When the gas is brought ashore after sea transport, it can either be stored in liquid form and or carried on in a pipeline. In the former case, the liquefied gas goes to a terminal where it can regain gaseous form; perhaps an FSRU: Floating Storage and Regasification Unit and pumped out to consumers to heat homes or used in industry.
Today, according to Aljazeera, there are 1.18 million km of pipelines - 30 laps around the earth. Pipelines run both on the seabed and, most often, on land. They constitute regional networks – there is no transatlantic pipeline. Pipelines cannot be laid at too great a depth, then such thick and unwieldy pipes are required that there is no room for any gas – already at 2,000 m it becomes difficult (result of discussions on the possible connection of Cyprus's Aphrodite field in the Mediterranean to Turkstream).

Electrical cables

Offshore wind power is being expanded. The Swedish government intends that offshore wind power will be responsible for half of our energy supply. The wind turbines, standing on the seabed or floating, deliver the electricity via cables to land. To what extent the wind turbines are vulnerable to sabotage etc. and their impact on operations at sea is beyond the scope of this article (see "Neither land nor sea" in this book.)
Power cables also play an important role in the European power grid. Sweden is connected to the continent through a number of cables that are used for export and import depending on the current electricity availability in the country. Gotland gets its electricity via two cables from the mainland; a third is on proposal.
Electric cables can of course be cut with the help of manned or unmanned underwater craft or by divers depending on the depth. The transfers are also likely to be vulnerable to cyber attacks.

Network cables

More than 95% of the world's data traffic goes through fiber cables on the seabed. This includes financial information worth enormous amounts of money. According to the UK's National Strategy for Maritime Security, the value of UK daily traffic alone is worth £1.3 trillion. "They form the backbone of the world economy" (Camille Morel, who wrote a doctoral thesis on the subject). Another important function is the connection to "cloud services". In the Baltic Sea there is an extensive network of cables, not least from Sweden (see the interactive Seabed Cables Map on the internet).
The fiber cables can also be used to detect passing submarines.
But why is it that the long-distance data transfer does not go via satellite? Because the amounts of data are too large for their limited bandwidth and it would be too expensive to send up enough satellites.
The cables form a worldwide network. In 2019, there were over 400 cables totaling 1.2 million km. The most important are the transatlantic ones, those that cross the Pacific Ocean, and Europe – China via the Suez Canal. In addition, South America - West Africa and Europe - West Africa to South Africa - 17,000 km!
The cables are generally owned by a telecom operator, for example Orange, who is thus formally responsible for protection and maintenance. Others involved are the manufacturer and the shipping company with the installer – for example Orange Marine, which has laid 230,000 km, according to its website, and which owns three cable vessels.

« The giants of the web » (Airbnb, Amazon, Meta, Google…) are increasingly active in the cable market.

The cables are physically fragile and can be damaged by trawlers, anchors, etc. They also contain valuable material for "recycling". It takes 1 to 2 weeks to repair a damaged cable. The cables also play an important role in Seabed Warfare.
In France, the cables are classified as "vital" because they provide services that are "indispensable" to the nation.

Seabed Warfare

According to Wikipedia, Seabed Warfare includes "operations to, from and across the seabed". More concretely in the form of: Anti-Submarine Warfare (ASW), mine warfare, sabotage of communications, and infrastructure, espionage as well as cyber attacks.
One of the great advantages of working on the seabed is that it is highly hilly and consists of different types of bottom sediments, stones etc. and that it is therefore easy to hide things such as mines, containers etcetera. A clear example is that no one ever managed to find the wreckage of Malaysian Airlines flight MH370 despite extensive search efforts.
According to US doctrine, Subsea and Seabed warfare is integrated into Full Spectrum Undersea Warfare. The US has the submarine USS Jimmy Carter, which is specially built to be able to lie still and has room for UUV (Unmanned Underwater Vehicle) which, among other things, should be able to intercept traffic in the data cables. Block VI Virginia class submarines, now under construction, also will have the capability to deploy UUVs for seabed warfare.
The US is working on a demining concept where a large number of mini-UUVs (150?) are released from a flying craft and can then search up to 10,000 square miles/day.
Russia traditionally has good underwater capabilities - remember the submarine violations of Swedish territory during the Cold War! A spectacular proof was when in 2007 the Russian flag was placed on the Lomonosov Ridge at a depth of 4261 m in the Arctic using a mini-submarine based on an icebreaker.
Russia has a submarine (Losharik), now laid up after a fire, intended for work at great depths; down to perhaps 2,500 m depth. It belongs to the Directorate for Deep Sea Research, GUGI. GUGI also has the "research vessel" Yantar. She is often seen over data cables in the Atlantic and is considered to have the ability to follow, sabotage, intercept and "debug" fiber cables on the seabed.
Russia is building a chain of listening stations ASS: Autonomous Seabed Station to protect the bastion around the Kola Peninsula in the Arctic.
China has the HSU-001 which is a large UUV considered to be intended for seabed warfare. The Chinese concept is the "great underwater wall". This will consist of a mixture of active and passive sensors, SARV (Semi-Autonomous Robotic Vehicle) and manned underwater vehicles.
The French mine clearance project SLAMF (Système de lutte anti-mines futur), in collaboration with Great Britain, will have capacity down to 6,000 m depth. The system consists of one or more command platforms and unmanned aerial vehicles (UUV) based on an unmanned USV (Unmanned Surface Vehicle).
Both New Zealand and the French intelligence services reportedly have the ability to intercept data in cables - this is thus a relatively widespread ability.
With the A26 Blekinge class submarines, Sweden gains the ability for seabed warfare through carried underwater vehicles. But they will only be two…

Doctrine, strategy

This author has found no trace of a doctrine for Full Spectrum Undersea Warfare and the new naval doctrine Advantages at Sea contains nothing concrete. The British National Strategy for Maritime Security also contains nothing about Seabed warfare. Sweden does not have a real maritime strategy – the document called Maritime Strategy does not discuss security or defense issues at all. But France has come a long way.

French strategy

In February 2022, a study report was submitted to then Minister of Defense Florence Parly with proposals for an "interministerial" strategy for large depths. Parly approved this. The aim is to guarantee French naval freedom of action within the territorial sea, economic zone, and in other important areas. In particular, it concerns the protection of the French second strike capability – the strategic nuclear submarines. The goal is to "know, monitor and act" in these areas down to a depth of 6,000 meters.
The report contains an action plan aimed at being able to carry out "Operations to control the underwater domain". These include both hydrographic surveys and operational functions. The first step is precisely to define different operation types and their meaning in more detail. There is thus a long way to go before an operational doctrine. The action plan includes both scientific investigations, materiel development and tactical development.
Protection of infrastructure on the seabed
The threat against infrastructure on the seabed is asymmetric insofar as it is "relatively" easy to attack but very difficult to protect. "It is impossible to protect 8,300 km of pipeline" (Dag Harald Claus, University of Ohio).
According to the website gCaptain, NATO had a meeting on this issue on September 30 without getting anywhere. However, it is likely that Seabed Warfare will now become a priority area for research and development.

Sweden needs to take a comprehensive approach to these issues – an underwater strategy or a strategy for maritime infrastructure. Not the least, a vulnerability analysis is needed as a basis for priorities. Constant surveillance of the sea is an obvious basis for all other activities.
Technically speaking, underwater reconnaissance is difficult. Searching for relatively small craft and the like requires high frequencies with, unfortunately, short ranges. It would be possible to let corvettes and submarines searching along particularly important areas. But that would be very resource-intensive. Further on, one can imagine a system of UUVs or fixed underwater sensors that search around important infrastructure while searching for mines or other intrusions in the important area. In practice, this probably means that it has to be an indication of some kind that can provide orientation for reconnaissance. Was this the case before the sabotageof the NordStream? From the reporting in the daily newspaper Dagens Nyheter, it appears that the navy had some form of indications in the area.


To summarize, the sea is gaining increasing economic and thereby strategic importance. As a consequence, the ability to work in and under water increases in industry and in the large navies.
Because underwater warfare is covert in nature, this area is ideal for hybrid warfare - a Russian specialty.
Sweden is not dependent on gas for its economy, but we are part of a Europe that is. The exact extent of our dependence on data cables is unknown but likely considerable. The electric cables are becoming increasingly important because we now have to import electricity. The future expansion of offshore wind power requires extensive studies to clarify vulnerabilities and methods of protection as well as regarding operational consequences in general.
The incoming defense committee must therefore study these issues and come up with measures. An underwater strategy or a marine infrastructure strategy needs to be developed. Such a strategy should be included in a National Maritime Strategy that deals with the entire maritime area – including defense and security in general.

Vad kan Sverige vidta får åtgärder för att förbättra vår förmåga till att etablera en lägesbild och skydda våra intressen på havsbotten?

Våra nya ubåtar av Blekingeklass kommer att kunna sätta in undervattensfarkoster – bemannade eller obemannade. Vi ska bara köpa in två ubåtar. Undervattensdrönare som programmeras att ligga och söka i viktiga områden är en annan möjlighet och på sikt sannolikt den bästa och långsiktigt mest kostnadseffektivt.

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