Russia: Poseidon Reactor Ran in Submarine Test

President Vladimir Putin announced a successful test of the Poseidon nuclear‑powered underwater drone, saying it was launched from a submarine and its onboard nuclear reactor ran for the first time and could not be intercepted. He claimed the reactor is far smaller than submarine reactors and that Poseidon's warhead significantly exceeds Russia's Sarmat ICBM; Russian sources described the system as an autonomous, deep‑operating, high‑speed torpedo with intercontinental reach. State and defense outlets gave specific performance claims—depths beyond 1 km, speeds up to about 70 knots (~124 mph), and a multi‑megaton warhead intended to create radioactive tsunamis—though independent verification is limited and Russia has not disclosed trial locations. Western analysts and arms‑control experts warn the program blurs deterrence, could cause environmental and humanitarian catastrophe, and that much of the public messaging is likely exaggerated. The announcement follows a recent test of the nuclear‑powered Burevestnik cruise missile, is listed by institutes such as SIPRI as an active program, and is widely seen as strategic signaling amid the war in Ukraine and heightened U.S.–Russia tensions.