• Does the recent string of subsea cable damage incidents around Taiwan point to malign actors out to disrupt?
• Or are they just random, accidental incidents that will only increase in number as more and more submarine communications cables are deployed? 
• Perhaps they are both, with rough weather and trawling apparatus providing plausible deniability for bad actors

Following a spate of submarine cable cuts, governments and network operators in South-east Asia are looking to increase subsea communications monitoring and resilience to minimise communications disruption as the AI age dawns and reliable, high-capacity connectivity becomes ever more important to economic stability and growth. 

Clearly much of South-east Asia, including Taiwan, is heavily reliant on subsea cable for its internal and external digital communications and the region is awash with new deployments, as we reported last year. The cables are increasingly backed up by redundant cables and wireless alternatives, including satellite and (for shorter distances) microwave links, but even so, cable outages are highly disruptive, costly to detect and expensive to monitor and fix, especially where bad weather interferes with their detection and rectification. An orchestrated series of cable disruptions could be catastrophic for countries in the region. 

Now, what appears to be a rising incidence of cable damage, especially around Taiwan, has stirred up a suspicion that China, which claims the island country as its own, may be conducting a low level campaign against the country’s increasingly critical submarine cable infrastructure. 

However, judging by the evidence, if there is a ‘campaign’, it’s sporadic rather than concerted, with a number of the seemingly suspicious incidents coinciding with rough weather and fishing vessels.

This rising cable incidents phenomenon is not just hitting Asia. The Baltic Sea in Europe is also a rich location for cable damage stories, though in this case the fidgety finger of suspicion tends to point to Russia.

As with Asia, geopolitical strife and rough weather are both present in the Baltic Sea, and with Germany, Sweden, Denmark, Poland, Estonia, Latvia, Lithuania, Finland and Russia all clustered around its edge and highly reliant on cable links to the rest of the world to support their rising digital and AI ambitions, the Baltic Sea’s extensive subsea infrastructure might be viewed as one giant cable damage incident just waiting to happen. 

Geopolitical suspicion abounds, especially following a recent spate of subsea cable damage incidents in the Baltic Sea. The Swedish authorities are currently investigating damage to a fibre optic cable running between Latvia and Sweden that is operated by the Latvian State Radio and Television Centre (LVRTC), Reuters has reported, and a vessel has been seized as part of the probe.  

At the end of 2024, the Estlink 2 subsea power cable between Finland and Estonia had been cut and, around the same time, three internet cables connecting the two nations were also damaged, with a fourth fibre optic cable between Finland and Germany going the same way. Russia was assumed to be the culprit and the Finnish Authorities even seized a Russian oil carrier, the Eagle S ship, in late December.

And in November, two subsea communications cables – one running between Lithuania and Sweden’s island of Gotland and the other between Finland and Germany – were severed and sabotage was suspected. Having tracked ship movements, international investigators suspected a Chinese ship’s crew had deliberately dragged an anchor to sever two Baltic cables. The incidents in late 2024 led NATO to launch new patrol and surveillance operations in the Baltic Sea.

But as The Washington Post reported, European and US intelligence agencies believe the damage was caused by maritime accidents rather than deliberate acts engineered by Russia and its allies. 

In Asia, a spate of similar incidents – all in quick succession – has caused a similar degree of consternation in Taiwan.

In one recent incident, communications cables running between Taiwan and China were severed. According to Politico, the Shunxin-39, which is a Cameroon-registered cargo ship but owned by Hong Kong-based Jie Yang Trading Ltd and headed up by a Chinese citizen, was acting suspiciously (by being 13 kilometres off Taiwan’s coast) just hours after an undersea cable was cut. The ship was ordered to return to shore to be investigated for signs of anchor dragging, which might have caused the cut. But bad weather prevented coast guard personnel from boarding and the vessel continued to South Korea. 

The Shunxin-39 incident is just the latest in a long list of apparent submarine cable-cutting hijinks in the region. In another incident, cable links between Taiwan and its nearby Matsu Islands were disconnected, apparently due to the corrosion of aging infrastructure exacerbated by bad weather, according to Taiwan’s Ministry of Digital Affairs (as reported by Nikkei Asia). 

However, the Taiwanese authorities didn’t fully buy in to the bad weather/aging infrastructure explanation. After the latest Matsu Island link failure (the fourth in quick succession), the ministry commented that it had “spotted that disruptions caused by fishing boats had increased in recent years” and furthermore the four recent recorded disruptions were greater in number than the three recorded in all of 2024, the ministry said.

It’s possible that Chinese actors are preparing to conduct a concerted cable-cutting campaign, perhaps by deploying new technology to do the dirty work – much has been made of China’s efforts to secure patents for a cable-cutting device that is designed to be towed along the ocean floor.

However, it’s also often pointed out that it’s sometimes necessary to cut subsea cables to perform maintenance operations, so developing a purpose-built cable cutter isn’t slam-dunk proof of felonious intent.

However, the spectre of disruptive submarine cable cutting in Asia looms large and the risks are real. The last few months have seen an accelerating stream of ‘Who snipped it?’ stories. So far, in most cases, the evidence of purposeful wrongdoing (by dragging an anchor) appears to be inconclusive. 

– Ian Scales, Contributing Editor, TelecomTV