Subsea cables crossing the ocean floor connect continents and carry nearly all digital data, financial transactions, and communications, but recent proximity by foreign vessels to this infrastructure near Ireland has raised security concerns, Al Jazeera reported.
About 75 percent of transatlantic subsea cables pass through or near Irish waters to connect North America with Europe. Ireland also hosts major data centres for United States technology multinationals including Google, Microsoft, and Meta.
In November 2024, the Russian ship Yantar was monitored near undersea infrastructure in the Irish Sea before the Irish Navy escorted it out of Ireland’s exclusive economic zone, as Al Jazeera reported. The United Kingdom Ministry of Defence described the vessel as a spy ship, while it is officially classified as an oceanographic research vessel.
Two months later, the UK Defence Ministry said that the Yantar had been caught loitering over critical undersea infrastructure in UK waters. In late 2025, the British government accused the ship of directing lasers at Royal Air Force pilots monitoring its movements in the North Sea.
Ireland Maintains Limited Maritime Monitoring Capabilities
Ireland maintains limited capability to monitor its waters, holding the lowest defence spending as a share of gross domestic product in the European Union and operating a navy without submarines. As a militarily neutral state, Ireland does not belong to NATO.
“[B]ecause of the end of the violence and the conflict in Ireland, and with the ceasefires and the peace agreement, we’ve had a peace dividend. So for the last 30 years, successive governments have really taken their foot off the accelerator when it comes to defence and security,” Senator Tom Clonan told Al Jazeera.
He added that Europe also enjoyed a peace dividend following the fall of the Berlin Wall, leaving Ireland as Europe’s weakest link in air, maritime, ground, and cyber domains.
Defence Minister Helen McEntee raised concerns over Russia’s shadow fleet, consisting of ageing and often uninsured tankers used to transport oil and evade Western sanctions. Moscow disputes the term shadow fleet as a political fabrication.
“Recent events in the Baltic Sea and the activities of Russia’s shadow fleet have highlighted the importance of ensuring that we have the legal framework necessary to respond to evolving threats,” McEntee said in March. The Irish government recently granted the navy expanded powers to board and inspect suspicious vessels.
Precedents in the Baltic Sea
Incidents involving shadow fleet vessels and cargo ships in northern European waters have heightened apprehension. In December 2024, authorities investigated a tanker suspected of belonging to Russia’s shadow fleet after power and telecommunications cables sustained damage in the Gulf of Finland.
In December 2025, a cargo ship sailing from St Petersburg under the flag of St Vincent and the Grenadines damaged telecommunications cables between Finland and Estonia. A Finnish court convicted its Russian captain and Azerbaijani boatswain of aggravated sabotage, as reported by Reuters and cited by Al Jazeera. Both defendants denied wrongdoing, and the conviction remains subject to appeal.
| Date | Vessel / Incident | Location | Reported Action |
|---|---|---|---|
| November 2024 | Yantar (Russia) | Irish Sea / Irish EEZ | Monitored near undersea infrastructure; escorted out by Irish Navy. |
| December 2024 | Unnamed Tanker | Gulf of Finland | Investigated after power and telecoms cables were damaged. |
| Late 2025 | Yantar (Russia) | North Sea | Accused of directing lasers at RAF pilots monitoring its movements. |
| December 2025 | St Vincent-flagged Cargo Ship | Finland to Estonia | Damaged telecommunications cables; captain and boatswain convicted of sabotage. |
Protecting the Digital Economy
Daniel Mulhall, Ireland’s former ambassador to the US, said that Ireland hosts 850 US multinationals operating large data centres, making the country an integral part of the Western digital economy. He told Al Jazeera that Ireland can no longer assume geographical protection.
“We are an integral part of the Western digital economy. And therefore, any sort of cyber threat to that economy is going to be potentially aimed at Ireland, or at least we could be victims of it, even if we’re not the prime target,” Mulhall told Al Jazeera, adding that Irish people are waking up to this complex reality.
Mulhall emphasized that securing the cables requires international cooperation rather than unilateral guarantees. “They’re the bloodstream of our economy. And if that bloodstream is interfered with, the economy will have serious trouble,” he said.
