Subsea cable tapping is undetectable with current monitoring technology

A nation-state with submarine capability can tap an undersea fiber optic cable by bending the fiber to extract light without cutting it, reading the data through photonic tapping techniques that introduce signal loss below the noise floor of the cable's optical monitoring. The tapped cable continues operating normally, and the cable operator has no indication that data is being intercepted. This persists because fiber optic monitoring systems (OTDR) measure signal loss to detect breaks, not the sub-0.1dB loss from a sophisticated photonic tap, and no commercial cable operator deploys the quantum-level monitoring that could theoretically detect such taps.