On 29 October 2025, Moscow revealed it had successfully tested the Poseidon nuclear-powered undersea drone, a weapon President Vladimir Putin described as “impossible to intercept.” The trial reportedly included the activation of the drone’s compact nuclear reactor, marking what the Kremlin called a major technological milestone. Poseidon, also known by NATO as Kanyon or Status-6, is part of Russia’s new generation of “super-weapons” unveiled in 2018 to counter Western missile defence systems. The announcement came only days after the Burevestnik nuclear cruise missile test, reinforcing Russia’s message of strategic defiance amid stalled peace talks with the United States over the war in Ukraine.
A deep-sea weapon beyond detection
According to Russian military sources, Poseidon measures about 20 metres in length, weighs 100 tonnes, and can dive to depths exceeding 1,000 metres while cruising at 60–70 knots (110–130 km/h). Powered by a miniature reactor “100 times smaller” than those on nuclear submarines, the drone is said to have virtually unlimited range. Its payload could reach 100 megatons, twice the yield of the Tsar Bomba, the most powerful nuclear device ever tested. Designed to detonate near coastlines, Poseidon could trigger a radioactive tsunami capable of devastating major ports and coastal cities. It is expected to be deployed from the Project 09852 Belgorod, a specialized nuclear submarine commissioned in 2022.
Strategic message and global concerns
President Putin claimed Poseidon’s destructive power exceeds that of the Sarmat ICBM, describing it as a symbol of Russia’s unmatched capabilities at sea. Western analysts, however, warn that the weapon blurs the line between strategic deterrence and doomsday escalation. U.S. President Donald Trump condemned the test as “irresponsible,” urging Moscow to end the war rather than unveil new nuclear systems. For maritime security experts, Poseidon represents a paradigm shift: a silent, autonomous nuclear threat operating deep beneath the North Atlantic—one that could redefine the balance of naval deterrence for decades to come.
