Cambridge University's latest research has produced interesting results. They analyzed 11 years of data and 68 actual failure cases regarding the impact of submarine cable cuts on the Bitcoin network, and the conclusion is surprisingly simple. Even if submarine cables are cut, Bitcoin remains almost unaffected.

Taking the incident off the coast of Ivory Coast in March 2024 as an example, seven cables were simultaneously severed, causing major regional internet chaos. But the impact on Bitcoin nodes was only about 5 nodes, roughly 0.03% of the entire network. Prices did not move, and consensus was not disrupted. Such a level of impact is within normal fluctuation ranges.

Researchers Wenbin Wu and Alexander Neumueller cross-checked 8 million Bitcoin node observations with data from 658 submarine cables. Of 385 cable failure reports, 68 verifiable cases showed that 87% had less than 5% node variation. The average impact was -1.5%, with a median of -0.4%. The correlation between node disruptions and Bitcoin price is almost zero.

What’s particularly noteworthy here is the approach of modeling Bitcoin as a layered network. Analyzing the structure of the physical connection layer, routing layer, and peer-to-peer overlay layer, they found that randomly severing cables would require 72–92% of all cables to fail—meaning over 10% of nodes would be disconnected—only if all cables failed simultaneously. In other words, unless nearly all international cables worldwide are destroyed at once, meaningful network splits in Bitcoin are unlikely to occur.

But here’s the truly important discovery: targeted attacks change the picture. Coordinated attacks aimed at top Autonomous Systems (ASNs) can reach the threshold by removing just 5% of routing capacity. The targets include hosting providers like Hetzner, OVHcloud, Comcast, Amazon Web Services, and Google Cloud. In the March 2026 Bitnodes snapshot, out of 23,150 accessible nodes, Hetzner hosts 869, Comcast and OVH each host 348, Amazon 336, and Google 313.

This isn’t simply “five providers can destroy Bitcoin.” Even if the public network were completely shut down, most nodes would continue to operate because Tor supports most of the network. However, coordinated actions could cause connection shocks and communication disruptions. That’s the real infrastructure risk.

Tor’s role is rapidly expanding. Usage was nearly zero in 2014, but by 2021 it reached 23%, in 2022 52%, and by March 2026, 63%. This increase coincides with multiple censorship events: Iran in 2019, Myanmar in 2021, and China’s mining bans in 2021. In other words, regulatory pressure has driven the network’s self-adaptation and accelerated overlay layer adoption.

The researchers built a four-layer model to handle this complexity. Including Tor relays as an independent network layer allowed for more accurate analysis. The results are intriguing: the four-layer model consistently produces high critical failure thresholds in the range of 0.02–0.10. While most of the consensus weight of Tor relays is concentrated in Germany, France, and the Netherlands—countries with extensive cable connections—disrupting connections to neighboring countries does not weaken relay capacity.

China’s influence is also significant. Bitcoin’s resilience hit a low of 0.72 in 2021, coinciding with peak hash power concentration. But after China’s mining ban in 2022, as infrastructure became more decentralized, the threshold rose to 0.88. Regulatory pressures promoted geographic redistribution and adoption of censorship-resistant infrastructure, both of which increased network robustness.

Here’s an interesting point: superficial centralization is due to measurement error. As Tor adoption increased, the sample of the public network became more concentrated in fewer locations, causing the index to rise. However, the actual share of Hetzner decreased from 10% to 3.6%. So, the apparent centralization reflects changes in sample composition, not real concentration.

In conclusion, concerns about submarine cable security will likely continue to grow. But in terms of Bitcoin, historical data shows that most cable events are noise. The truly critical infrastructure issues are policy adjustments, cloud service shutdowns, and hosting restrictions that could impact autonomous system connectivity through coordinated actions.

Bitcoin is not as fragile as critics imagine, but it’s not completely detached from infrastructure either. The network shows a graceful degradation rather than catastrophic collapse. Censorship pressures have driven overlay layer adoption, strengthening resilience against coordinated risks. The threat model of submarines cutting cables ignores more immediate bottlenecks—where, without dramatic submarine actions or warfare, a small group of networks could cause temporary disruptions through coordinated behavior.