Russia covertly assists Iran in developing supersonic cruise missiles under C430L program

Under the secretive C430L initiative that began in 2023, Russia has been supplying Iran with technical assistance to create supersonic cruise missiles, chiefly by helping perfect a ramjet propulsion system capable of sustaining several times the speed of sound. The programme is coordinated by Rosoboronexport and the rocket design bureau NPO Mashinostroyenia, which sent senior engineers to Tehran and exchanged extensive data on fuel, combustion stability, air intake and nozzle design.

Iran has already built and flight-tested the ramjet, though no complete missile has been deployed. Experts say such weapons could threaten US Navy vessels in the Gulf, where advanced air-defence systems are present. The cooperation continued into 2026, with Russian officials preparing technical reports and negotiating the next development phase, despite the ongoing US-Israeli war against Iran. The transfer represents a rare high-level strategic technology exchange between Moscow and Tehran.