Researchers from the Cambridge Centre for Alternative Finance have revealed that nearly three-quarters of all undersea fibre optic internet cables (which carry about 99% of international internet traffic) would need to fail to significantly impact Bitcoin. The study used P2P network data from 2014 to 2025 and 68 verified cable fault events to assess Bitcoin’s physical infrastructure resilience. The critical failure threshold for random cable removal was found to be at 0.72 to 0.92, meaning 72% to 92% of all “inter-country” submarine cables would require to fail before more than 10% of network nodes disconnect. However, researchers found that the Bitcoin network was more vulnerable to targeted attacks on certain subsea cable chokepoints, with a critical failure thresholds of 0.20. The researchers also found that Tor (The Onion Router) creates a compound barrier to disruption given its high concentration of relay infrastructure in well-connected European countries. They concluded that 87% of the 68 verified historical incidents caused less than a 5% node impact, and that the geographic diversification of BTC mining has not significantly impacted infrastructure resilience.