U.K. Shares Stone Cloak Jammer Design With Ukraine
Get the Geopolitics newsletter
Daily geopolitics — wars, elections, sanctions, the diplomatic moves that move markets. Free.
- The U.K. announced a tech-sharing deal on Saturday letting Ukraine mass-produce Stone Cloak, a roughly tablet-sized British-designed radar jammer intended for long-range strike drones
- Stone Cloak was first publicly revealed as President Volodymyr Zelenskyy met with British PM Andy Burnham at the Sea Breeze joint naval exercise in Portsmouth, where Ukrainian, U.S. and British sailors focused on countering Russian air defenses
- Ukraine has already deployed British-built versions of Stone Cloak on long-range strike drones this year, with the new agreement enabling faster scaling across its drone forces
- The Storm Shadow missile took six years to develop and averages about $2 million per unit; unlike Stone Cloak, its design technology was never transferred to Ukraine, which received only the finished missiles
- The Breakstop program, a 2024 U.K.-Ukraine joint effort to develop a new long-range strike drone with streamlined requirements, is set to deliver missiles for frontline use later this year—less than 24 months from concept to deployment
- Ukraine separately announced its own long-range strike missile, the Flamingo (FP-5), capable of hitting Russia at a cost far lower than the Storm Shadow
- Retired U.S. Air Force officer Jeffrey Fischer told Defense One that Ukraine's adaptation cycle can implement battlefield lessons in under 10 days, a pace he says is unmatched in his seven combat deployments
Why it matters: By moving from donating $2 million Storm Shadows to transferring Stone Cloak's intellectual property, the U.K. is letting Ukraine scale electronic warfare tools domestically while gaining access to a sub-10-day battlefield adaptation cycle Fischer calls unprecedented. The parallel Breakstop program delivering missiles in under 24 months and Ukraine's cheaper Flamingo show the cost-per-strike gap between allied donations and Ukrainian production is narrowing fast.
