For two years, the front line had been a kind of radio war. Whoever jammed harder, won. Fibre-optic drones ended the argument by ignoring it.
When Russia first fielded fibre-optic FPVs in the spring of 2024, the device looked like a curiosity. An unspooling reel of optical fibre, two kilometres on the original prototypes, dragged behind a quadcopter as it flew. The cable carried the video feed and the control signal both. It was physically immune to radio jamming. It was undetectable by direction-finding equipment.
By 2025 the curiosity was the defining counter-electronic-warfare innovation of the war. The K-2 regiment's commander declared 2025 the year of fibre-optics, and Russia is winning the niche by volume — doubling production in September to more than fifty thousand units a month, supplied by a domestic fibre plant in Saransk and Chinese cable spools. Cable lengths have grown from five-to-ten kilometres to demonstrated prototypes of forty to sixty-five.
In October of 2025, a Russian fibre-optic drone struck inside the city of Kramatorsk, nineteen kilometres behind the front line. The implication is the rule of the new front: no point within roughly twenty-five kilometres of contact can be considered safe rear area. Sheet VII — the kill zone — is the doctrine that follows.
Ukraine has integrated fibre-optic FPVs onto its Sea Baby surface drones and is mass-procuring them, though it depends on Chinese cable imports. The strategic vulnerability of that dependency is the subject of Sheet XIII.