Tensions between Russia and the UK have escalated once again after one of its spy vessels in the North Sea was caught shining lasers at RAF pilots in a “deeply dangerous” act of provocation.

Britain says Russia’s Yantar ship targeted RAF pilots—but the real threat lies under the sea. How vulnerable are the UK’s vital undersea cables to attack?

The vessel, designed for gathering intelligence and mapping crucial undersea cables, is loitering off the northern coast of Scotland, having entered wider UK waters over the last few weeks.