Beyond the Glass Thread: The Challenge of Surpassing Fibre Optic Drones

Sunday 18 January 2026

Amongst the many technological adaptations that have emerged during the Russian invasion of Ukraine, the fibre optic drone stands out as a distinctly wartime improvisation with far-reaching implications. By replacing radio-frequency command links with a physical fibre optic cable spooled from the drone itself, Ukrainian engineers and operators have produced a system that is remarkably resistant to many of the countermeasures upon which modern armies have come to rely. The question now confronting military planners is not simply how to defeat such drones, but how to surpass them with a superior weapons concept. That task is proving more difficult than first appears.

The appeal of fibre optic drones lies in their brutal simplicity. They are immune to electronic jamming, largely invisible to electronic intelligence systems and difficult to detect until they are already close to their target. The control signal travels along a hair-thin strand of glass, impervious to electromagnetic interference and unaffected by the crowded electronic battlespace that now characterises the front line. For a defender accustomed to suppressing drones with electronic warfare, this represents an uncomfortable regression to a more physical form of combat, in which signals cannot simply be silenced at the push of a button.

Any weapon seeking to surpass fibre optic drones must therefore solve several intertwined problems at once. The first is resilience. A successor system must be at least as resistant to jamming and interception as a fibre optic link, yet without inheriting its limitations. Fibre optic drones are constrained by the length and fragility of their tether, which limits range, altitude and manoeuvrability. They are best suited to relatively short, direct attacks against fixed or slow-moving targets. A superior system would need to break free of these constraints without returning to the vulnerabilities of radio control.

This leads to the second challenge: autonomy. One obvious route beyond fibre optic control is the development of drones capable of operating with minimal or no real-time human input, relying instead on onboard processing to navigate, identify targets and strike. Yet autonomy introduces its own difficulties. Reliable target recognition in the chaos of the battlefield remains an unsolved problem, particularly when the ethical and legal consequences of error are so grave. Even setting aside moral considerations, fully autonomous weapons demand sensors, processors and software robust enough to function under fire, in poor weather and in deliberately degraded environments. These systems are expensive, complex and prone to failure in ways that a simple fibre optic link is not.

A third obstacle is cost and scalability. Fibre optic drones are, by modern military standards, cheap. They can be assembled from commercially available components, modified in workshops close to the front and deployed in large numbers. Any weapon intended to surpass them must either match this affordability or offer such a decisive advantage that higher costs can be justified. History suggests that systems which are too precious to lose are often used too cautiously to shape the battlefield. The success of fibre optic drones is inseparable from the willingness to expend them.

There is also the problem of counter-countermeasures. Fibre optic drones have flourished because they exploit a gap in existing defensive doctrines. Once that gap is closed, whether through physical barriers, rapid-fire close-in weapons or improved visual detection, their effectiveness may decline. A successor system must anticipate not only today’s defences but tomorrow’s adaptations. This demands a level of foresight that is difficult to achieve in a war where innovation is often reactive rather than strategic.

Finally, there is the human factor. Fibre optic drones still place a trained operator directly in the loop, allowing for judgement, improvisation and restraint. Weapons that seek to surpass them by removing or marginalising the human operator risk losing these qualities. In a conflict where civilian presence, complex terrain and fluid front lines are the norm, the value of human decision-making remains high. Replacing it without sacrificing effectiveness or legitimacy is a formidable challenge.

In this light, the difficulty of surpassing fibre optic drones becomes clearer. They represent not a technological pinnacle, but a local optimum: a solution well matched to the conditions of the current war. To move beyond them requires advances in autonomy, resilience and affordability that have eluded even the most well-funded military programmes. Until such advances are realised, the thin strand of glass trailing behind a low-flying drone may continue to symbolise an uncomfortable truth for modern armed forces: that sometimes the most effective weapons are not those that are most advanced, but those that are most appropriately adapted to the realities of war.