This weapon represents a radical evolution in nuclear deterrence and underwater warfare, raising significant strategic and environmental concerns worldwide.
The Poseidon, often referred to by NATO as “Kanyon,” is an autonomous underwater drone powered by a compact nuclear reactor, allowing it to travel at high speeds, up to 100 knots (approximately 115 mph), and operate at extreme depths around 1,000 meters.
According to Putin, the test involved launching the weapon from a submarine carrier, after which its nuclear propulsion system activated, allowing it to travel a significant distance underwater autonomously.
What distinguishes the Poseidon is not just its speed and stealth but its strategic payload: a multi-megaton nuclear warhead speculated to be a cobalt bomb. This type of warhead is designed to maximize long-lasting radioactive contamination, far beyond the explosive blast itself.
Poseidon’s detonation near coastal cities could trigger massive waves, often described as ‘radioactive tsunamis’, which would inundate port cities with radioactive water, potentially rendering vast areas uninhabitable for decades.While large tsunamis are typically directional, spreading energy along a singular path, an underwater nuclear explosion generates waves radially in all directions, dispersing energy but still sufficient to cause destructive flooding. For reference, the 2011 Japan tsunami, which devastated parts of the eastern coast, released energy vastly greater than the estimated upper limit of Poseidon’s warhead. However, the combination of physical destruction and radioactive fallout heightens its destructive potential uniquely.
Putin hailed the weapon as unrivaled in speed and power, surpassing many existing missile systems in strategic deterrence value. He framed the test as a necessary response to geopolitical shifts, including the US withdrawal from the 1972 Anti-Ballistic Missile (ABM) Treaty and NATO’s expansion. The Poseidon’s ability to circumvent missile defense systems reflects Russia’s strategic intent to maintain credible deterrence capabilities with novel nuclear technologies.
Environmental and humanitarian experts warn the weapon’s radioactive contamination could have catastrophic long-term consequences for marine ecosystems and human populations, complicating any potential post-conflict recovery. Furthermore, international law experts suggest that using a weapon designed explicitly to cause widespread, severe radioactive contamination and flooding could violate laws governing warfare due to its indiscriminate and lasting nature.
Amid the announcement, US President Donald Trump criticized the test as “not appropriate” and called on Putin to focus on resolving ongoing conflicts, particularly the war in Ukraine. However, Putin dismissed these comments, emphasizing the test as a necessary precaution in an evolving global nuclear landscape.
The Poseidon is deployable from Russia’s Belgorod and Khabarovsk-class carrier submarines, each capable of carrying multiple such torpedoes, showcasing Moscow’s advancing underwater second-strike capability.