Are New Zealand’s Submarine Cables Safe?
In recent months, there has been a worrying trend of submarine telecommunication cables being damaged around the world. This has raised serious concerns about the vulnerability of these crucial undersea networks, particularly for countries like New Zealand that rely heavily on them for internet connectivity.
In November 2024, two submarine cables in the Baltic Sea—the BCS East-West Interlink and the C-Lion1 fibre-optic cables—were damaged. Officials suspect a Chinese ship deliberately dragged its anchor over the cables, although this has not been confirmed.
Just days before Christmas, an electrical cable between Estonia and Finland was also damaged, with the possibility of sabotage not ruled out. The ship involved, carrying Russian oil, was flying the flag of the Cook Islands, bringing the issue closer to home for New Zealand.
More recently, Swedish authorities seized a cargo ship suspected of sabotaging a cable connecting Sweden and Latvia in the Baltic Sea. Earlier this month, a Chinese ship allegedly damaged a cable linking Taiwan and the US by dragging its anchor.
While there’s no conclusive evidence of a coordinated campaign, these incidents hint at a chilling possibility: the rise of "grey zone" warfare, where states engage in activities below the threshold of traditional conflict.
A Legal Grey Area
The situation is further complicated by international law. Nations only control the sea bed within 22 kilometers of their coast. The 1884 Convention for the Protection of Submarine Telegraph Cables makes it illegal to damage undersea cables, but enforcement is challenging, particularly in international waters.
New Zealand’s Vulnerability
New Zealand relies on three cable networks and five physical cables to connect with the world. Thankfully, the original Southern Cross network was designed for resilience, forming a figure-eight shape to ensure operation even if a segment is cut. This has proven valuable in the past, with the network recovering successfully from at least two such cuts without major disruption.
However, deliberate sabotage or the kind of "accidental damage" that seems to be increasing raises new concerns. While New Zealand has significant redundancy in its connections, this primarily benefits everyday internet users. Critical infrastructure and cloud companies might face more significant disruption if multiple cables are compromised.
Satellite backup options exist but have limitations. Latency is high, and bandwidth is limited, insufficient to handle today’s data demands.
Preparing for the Future
NATO is aware of the threat. Sources indicate the alliance is building a fleet of submarine drones to monitor cables. New Zealand, while geographically distant from the current hotspots, must also consider its vulnerabilities and potential responses.
Strengthening existing infrastructure, exploring alternative connections, and engaging in international collaboration to address the threat of deliberate cable damage will be crucial in ensuring New Zealand’s digital future remains secure.
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