The influential center-right think tank Policy Exchange has published a report warning of the dangers of attacks on submarine telecommunications cables, written by Rishi Sunak, a member of the UK Parliament.

While submarine cable networks are mostly redundant, the report warns that well-orchestrated attacks could cripple the economy or put military communications at risk.

That sinking feeling

Cable laying ship
Cable laying ship – Alcatel-Lucent Submarine Networks

The report, titled ‘Undersea Cables: Indispensable, insecure,’ details various threats to submarine cables, which account for 95 to 97 percent of transoceanic digital communications.

Usually, cuts to submarine cables are accidental, with the report noting: “As with so many things, the most straightforward threat to undersea cables is posed by unintended error rather than conspiracy. The United Nations estimates that between 100-150 cables are damaged annually with the most frequent culprit being fishing activity.

While potentially costly to their owners, accidental faults of this kind pose a relatively limited direct threat to advanced economies thanks to the highly diversified nature of their cable networks.

“Britain, for example, is connected to mainland Europe and the Unites States by more than 30 fibre-optic cables, meaning that if one or two are damaged by fishing activity, there is plenty of spare capacity for data to be rerouted without causing disruption.”

The real danger, the report claims, is from malicious attacks that aim to take out multiple cables at once. It states: “While the diversity of cable connections to economies like the UK and US offer enough resilience to ensure that accidental damage does not pose a realistic threat of a catastrophic outage, co-ordinated sabotage on multiple cables has the potential to pose a major threat to the UK.

“The threat this poses is illustrated vividly by the example of the submarine cable connections between Europe and India. If one or two cables were damaged accidentally, functionality would be unlikely to be significantly impaired thanks to spare capacity. Cut three cables, however, and India would lose 70 percent of its data traffic with Europe. Overall, the world’s critical cable infrastructure is dangerously concentrated.”

One case highlighted in the report is that of the December 2008 Italy-Egypt accident, when shipping traffic cut three cables, reducing connectivity by 80 percent.

With the US military relying on commercial cable networks for the majority of its strategic communications, this impacted the ongoing Iraq war - notably the US Air Force drone warfare efforts: “The impact of the outage was severe. Lieutenant Colonel Donald Fielden of the 50th US Communications Squadron stated that the cable breaks had cased UAV flights operating from Balad Air Force base (the US’ largest in Iraq) to decrease from ’hundreds of combat sorties per day’ to ’tens’.”

Closer to home, the impact of cable damage would most heavily be felt by the financial sector, with roughly 213 cables carrying an estimated $10 trillion of financial transfers and 15 million financial transactions every day.

The report states: “Put simply, if an adversary were to succeed in executing a successful attack against Britain’s undersea cable infrastructure the result would be financial disaster on an unprecedented scale.”

Beware of the bear

Prime Minister Theresa May with Russia's Vladimir Putin
Prime Minister Theresa May with Russia’s Vladimir Putin – The Kremlin

As for who would have an interest in wreaking havok in international waters, the report repeatedly points a finger at Russia, whose Yantar class intelligence ships and auxiliary submarines include the necessary equipment for cutting submarine cables.

”The prospect of a Russian intelligence ship lurking near American waters - armed with submersibles capable of cutting undersea cables - might seem more at home in a Tom Clancy novel than the pages of The New York Times,” the report says.

”Yet in late 2015, American military and intelligence officials spoke openly of a sustained pattern of Russian submarines and vessels ’aggressively operating’ near cables, highlighting that the vital lines of communication are vulnerable to attack by Russian naval forces. It was reported that US officials were ’monitoring significantly increased Russian activity along the known routes of cables’.”

In a foreword, Admiral James Stavridis, USN (Ret), former NATO Supreme Allied Commander Europe, notes that the overwhelming military advantage of NATO forces over Russian troops could result in the country avoiding conventional conflict and focusing instead on attacks against asymmetric targets, like fiber-optic cables. ”Recent reports make clear that Russian submarine forces have undertaken detailed monitoring and targeting activities in the vicinity of North Atlantic deep-sea cable infrastructure.

”And as another example of Russian interest in asymmetric targets, it is worth remembering that in Crimea, Russia successfully took control of land based communications infrastructure early in its annexation of the peninsula.”

Stavridis added: ”Hybrid warfare has traditionally been land-based, but as I have argued previously, this is about to change and we should prepare for increased maritime hybrid activity.”

And then there’s the risk of terrorism.

Non-state actors would struggle to impact the same number of cables as a nation-state, although this is still a possibility - the location of cables is made public to avoid fishing vessels accidentally dropping anchors on them, something a terrorist could do intentionally. There are also certain bottlenecks around the world where several cables are in close proximity.

Another, perhaps easier to reach, target for terrorists could be found in cable landing stations. ”Partly in order to reduce costs, and partly because it is rare to find a location with the geographical suitability to be a landing site, multiple cables frequently share a single landing site through which data is re-routed to users. This practice has led to the development of a number of major on-land choke points which, according to former Deputy Undersecretary of the US Navy Robert Martinage, make a major attack ’surprisingly feasible’,” the Policy Exchange report states.

”This clustering has led to significant reduction in the number of sites that would be necessary for a hostile actor (e.g. a terrorist group) to target in order to pose a potentially existential threat to the UK. Indeed, according to secret documents released by Wikileaks in 2010, the US State Department lists a number of UK trans-Atlantic cable landing facilities as overseas infrastructure ‘critical’ to US security; an honour shared in the UK only by military facilities.”

Unlike military facilities, however, landing sites are usually left relatively unprotected.


With readers suitably unnerved by a litany of threats, the report makes nine UK-focused recommendations:

  1. Strategic Defence And Security Review - The next Strategic Defence Review should take into account the threat to attacks on submarine cable infrastructure, the report states.
  2. National Risk Assessment and Risk Register - The next National Risk Assessment (held every two years) should look into the risk of these attacks.
  3. Secure Landing Sites - The government should instruct the Centre for the Protection of National Infrastructure (CPNI) to carry out a full review of how landing sites are protected, with the sites potentially given similar treatment to that of other critical infrastructure such as national power generating capacity.
  4. Establish Cable Protection Zones - The report states that Britain should establish Australian-style Cable Protection Zones (CPZs) around its coast in areas with cable corridors. Such zones ban certain anchoring and fishing, require greater disclosure by vessels inside them and give the Coast Guard stronger powers and penalties. Britain should also encourage such CPZs in the Mediterranean and Suez.
  5. Deploy Better Monitoring Equipment on Cables - As underwater vehicles looking for cables to cut would likely use high-frequency sonar, the report states that cable laying companies could be “required to place relatively cheap sensors that detect sonar frequencies near key undersea infrastructure and along cable routes. If the sensors were tripped, they could alert nearby coast guard or navy assets.”
  6. Broaden Geographic Diversity - The report wants Britain to use its influence as a key geographic bridge between the US and Europe to work with the private sector and overseas governments to increase the geographic diversity of submarine cables.
  7. Increase the Supply of “Dark Cables” - The government could encourage backup cable systems and redundant networks by offering tax incentives and working with private telecommunications companies.
  8. Strengthen International Law Protecting Cables - The report states that the UK should push for the adoption of a “new international treaty that protects submarine cables, making international interference with them an international crime, and include provisions for mutual cooperation on enforcement against such crimes.”
  9. Increase NATO Naval Exercises and Review Maritime Capabilities - The report wants the UK to press at the NATO level to promote the undertaking of naval exercises and war games to hone potential responses to an attack on undersea cable infrastructure.

In response to the report, a UK government spokesperson said the issue was being taken “extremely seriously.”

They added: “We are continuously working with industry to ensure our sub-sea cable network is secure and have a variety of tools to monitor potentially-hostile maritime activity.”