The cables linking Svalbard to mainland Norway were not cut this spring. Even so, an encounter nearby raised an awkward question about how they would be defended if they were. Reuters reported, citing two Western officials, that British, Norwegian and American forces confronted Russian submersibles practising with equipment said to disable cables without leaving obvious traces. The officials did not explain how it worked. Russia denies planning sabotage, and no attack was confirmed. What makes the account unsettling is the possibility it describes. A country might lose a connection and struggle to establish whether a rival had touched it at all. By the time investigators knew, the vessel might be gone.
There is more at stake than the internet on a remote island. According to the International Telecommunication Union, seabed cables carry more than 99 per cent of international data traffic. Data travels along physical routes and comes ashore at fixed points. Often it can be diverted if one line fails; a place with few routes is less fortunate. The same UN agency records more than 200 faults worldwide each year. Anchors, fishing and earthquakes can all cause damage, so an unexplained break is hardly proof of an attack. For someone contemplating interference, that ordinary background of accidents offers cover.
Governments cooperate in the Arctic on shipping, research and the environment. The Arctic Council expressly excludes military security from its remit, leaving that question to governments and alliances operating in the same waters. With cables, the division is even more pronounced. Companies own and repair them, while governments investigate crimes and navies watch for threats. A ship may be registered in a third country. None of these arrangements is inherently defective, but together they can leave nobody ready to act on the whole picture when a line goes down. That is the structural resemblance to the Arctic. One is a region and the other a network crossing many regions, but civilian activity and strategic competition share both spaces.
In the Baltic, the limits of watching the sea have already become clear. After several communications and power links were damaged, NATO launched Baltic Sentry in January 2025, putting more aircraft and ships into the area. Patrols can establish that a vessel passed over a cable. They cannot establish from that fact alone whether its anchor dragged accidentally, or whether anyone on board meant it to. Nor have all Baltic incidents been shown to have the same cause. A cable operator may know when a fault occurred, while information about the ship is held elsewhere. Surveillance helps, but it does not turn a suspicion into proof or give NATO the authority of a national investigator.
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Taiwan shows why it is just as dangerous to assume every break is innocent. A Taiwanese court convicted a Chinese captain in 2025 of deliberately cutting a cable. The conviction established what the captain did, not that Beijing ordered him to do it. Then, late in the same year, an earthquake disrupted six international cables, according to Taiwan’s digital ministry. One event involved deliberate damage; the other did not. Both required repairs, but only the first raised a question of responsibility. Taiwan cannot wait for certainty before keeping its communications working, and it cannot make a wider accusation simply because a suspect ship was nearby. A deliberate cut can put pressure on a government without giving it proof to accuse another state. It must respond immediately, even when the political meaning of the incident remains disputed.
The law is not absent. Under the UN Convention on the Law of the Sea, states may lay cables across the continental shelf and must make certain damage to high-seas cables an offence when committed by their ships or nationals. Yet those provisions do not let any coast guard board a foreign vessel wherever it likes. Investigators also have to establish what the ship actually did. A drag mark on the seabed, a company’s record of the fault and a vessel’s movements may be held by different people in different jurisdictions. International law provides a basis for protection and punishment; it cannot collect evidence before a ship leaves port. That practical gap matters more than calling the seabed an ungoverned commons.
European governments have begun to recognise the problem. The EU’s 2025 cable security plan proposes exercises with NATO and coordinated investigations, while admitting that the lawful grounds for stopping or boarding suspect vessels need careful assessment. The Commission has also committed funding for regional cable hubs in the Baltic and Mediterranean. These steps should make it easier to detect damage and share information. Whether they will do so fast enough is a different question. An extra patrol may see a ship, and a repair crew may restore service, but neither can decide on its own who caused the break. That decision requires evidence strong enough to survive public scrutiny, especially if a government intends to accuse another state.
There is a good argument for concentrating on backup routes and quicker repairs instead. They would keep people connected after an earthquake as well as after sabotage. But resilience alone would leave a deliberate attacker free to try again. Governments also cannot deter interference by calling every accidental fault an attack. The task is to restore a damaged connection while preserving enough evidence to tell those cases apart. Taiwan’s earthquake and the Baltic investigations show why both parts matter. One keeps daily life working; the other prevents uncertainty from becoming a permanent advantage for whoever is willing to exploit it.
The Baltic is a reasonable place to find out if Europe’s plans close that gap. By 31 March 2027, the Commission and Baltic governments should publish an unclassified account of a joint exercise. It should report whether an operator’s fault alert and the relevant ship records reached investigators within 24 hours, and whether officials knew which authority could lawfully act before a vessel left. They need not reveal cable routes or intelligence sources. A successful test would show that civilian operators and security agencies can work together under existing rules. If no exercise is held, the weakness exposed near Svalbard will still be there. The next suspected cut could force a government to respond before its investigators know what happened.
