In February 2024, Vladimir Putin sat for an interview and casually confirmed something Western intelligence agencies had tracked for years: Russia had successfully tested Poseidon, a nuclear-powered underwater drone designed to cross entire ocean basins autonomously and detonate near an enemy’s coast. The weapon was launched from a carrier submarine, Putin said, and operated under its own nuclear propulsion. He offered no date, no coordinates, no depth figures. Just the confirmation that it worked.
That test brought renewed attention to the submarine reportedly built to carry Poseidon into service: the Khabarovsk, a Project 09851 boat that defense analysts and open-source intelligence trackers estimate at roughly 135 meters in length, with capacity for up to six of the nuclear-armed torpedoes. Those figures, widely cited in defense media as of June 2026, have not appeared in any declassified Russian or American technical document. But the program behind them is no longer speculative. The U.S. government has treated it as real at the highest levels of defense policy, and the strategic implications are already reshaping how NATO thinks about undersea warfare.
What primary sources actually confirm
Putin’s own words remain the strongest single piece of public evidence. His description of a successful launch and nuclear-powered transit established that Russia had moved past blueprints and into live trials. Russian state media went further, characterizing Poseidon as a weapon meant to detonate near enemy coastlines and generate a radioactive tsunami. Putin did not use that exact phrase, but he did not dispute it either.
On the American side, the program shows up in formal government records. A stenographic transcript from an October 2019 hearing of the U.S. Senate Armed Services Committee refers to an “autonomous underwater vehicle known as Poseidon,” treating it as an established Russian weapons effort rather than a rumor. That phrasing matters. It signals that senior defense and intelligence officials had already assessed Poseidon as credible enough to warrant sworn congressional testimony.
The Pentagon’s 2018 Nuclear Posture Review, archived by the National Security Archive at George Washington University, provides additional context. The review cataloged novel Russian delivery systems, including underwater drones, among Moscow’s strategic modernization priorities. It did not name Poseidon or Khabarovsk specifically, but the category it described maps directly onto the program Putin later confirmed.
Together, these records establish a verified chain: Russia built and tested a nuclear-powered underwater drone, launched it from a submarine, and the United States treated the program seriously enough to discuss it in both classified and unclassified settings at the highest levels.
The Khabarovsk question
The submarine itself is where hard evidence thins out. The 135-meter length, the six-torpedo payload, the Project 09851 designation: all of these details originate from defense journalists, commercial satellite imagery of the Sevmash shipyard in Severodvinsk, and open-source intelligence communities that have tracked the hull’s construction over several years. No official Russian or American disclosure has confirmed the specifications.
Khabarovsk is not the only submarine linked to Poseidon. The Belgorod, a converted Oscar-II class boat designated Project 09852, was commissioned into the Russian Navy in 2022 and is widely reported as the first operational Poseidon carrier. Belgorod is significantly larger, stretching an estimated 184 meters, and its existence is better documented through Russian Navy commissioning ceremonies and official statements. Khabarovsk, by contrast, appears to be a purpose-built, smaller carrier designed from the keel up for the Poseidon mission. Whether it has completed sea trials, entered active service, or begun deterrence patrols remains unknown from public sources as of June 2026.
That gap between announcement and deployment is worth taking seriously. Russia has a pattern of unveiling weapons programs years before they reach operational status. Putin first revealed Poseidon publicly during his March 2018 address to the Federal Assembly, alongside the Burevestnik nuclear-powered cruise missile (NATO reporting name: SSC-X-9 Skyfall). More than eight years later, neither system has been confirmed as fully deployed in a combat-ready configuration by any independent Western assessment.
The “radioactive tsunami” debate
Perhaps no aspect of Poseidon generates more public fascination, or more scientific disagreement, than the claim that it could produce a radioactive tsunami capable of devastating a coastline. Russian state television has aired graphics showing enormous waves engulfing cities, and some Western media outlets have repeated the framing without much scrutiny.
Independent physicists have pushed back. An underwater nuclear detonation, even a very large one, does not necessarily produce a tsunami in the way an earthquake-triggered seismic event does. Water absorbs enormous amounts of energy, and the wave dynamics of a point-source explosion differ fundamentally from the tectonic displacement that drives natural tsunamis. Several analysts have argued that the more realistic threat is severe radioactive contamination of port infrastructure, naval bases, and coastal waters, devastating in its own right, but different from the cinematic wall-of-water scenario.
No named Western defense agency has published a consensus technical assessment resolving this debate in the public domain. The distinction matters for NATO planning: a weapon that irradiates a harbor requires a different defensive posture than one that physically destroys a coastline with a wave. For now, the honest answer is that the exact destructive mechanism remains contested among credible experts.
What Washington’s response tells us
Sometimes the most reliable signal about a foreign weapons program is not what the adversary claims but how your own government reacts. By that measure, Poseidon registers as a serious concern.
Beyond the Senate hearing and the Nuclear Posture Review, the broader pattern of U.S. and NATO investment points toward genuine worry about undersea threats. The alliance has increased spending on anti-submarine warfare capabilities in recent years, including upgrades to sonar networks, expanded deployments of P-8A Poseidon maritime patrol aircraft (the naming coincidence is not lost on defense watchers), and investment in unmanned undersea surveillance vehicles. The United Kingdom and Norway have reinforced monitoring of the GIUK Gap, the chokepoint between Greenland, Iceland, and the UK through which Russian submarines must pass to reach the open Atlantic.
None of these investments are attributed solely to the Poseidon torpedo program. Russia’s broader submarine modernization, including new Yasen-M class attack boats and Borei-A class ballistic missile submarines, drives much of the spending. But the emergence of a novel, hard-to-detect undersea nuclear delivery system adds a layer of complexity that traditional anti-submarine doctrine was not designed to address. A slow-moving autonomous drone that hugs the ocean floor presents a fundamentally different tracking problem than a submarine that must periodically communicate with its command authority.
Where Poseidon fits in deterrence theory
Traditional nuclear deterrence rests on a straightforward if terrifying logic: each side must believe the other can absorb a first strike and still retaliate with enough force to make aggression irrational. Submarine-launched ballistic missiles have served as the backbone of that second-strike guarantee for decades, hiding deep beneath the ocean where a preemptive attack cannot reach them.
Poseidon fits into this framework as an alternative path to the same end. If Russia’s land-based missiles were destroyed and its ballistic missile submarines were tracked and neutralized, a pre-positioned autonomous drone sitting on the seabed could still deliver a retaliatory strike. In that sense, it reinforces deterrence rather than overturning it.
But the signaling is different. Because Poseidon is described as slow-moving and potentially pre-deployed, it introduces a “doomsday backstop” dynamic. An adversary considering a first strike would have to account for weapons already in position, not just weapons that could be launched in response. That uncertainty complicates preemption calculations in ways that favor the defender, which is precisely Moscow’s intent.
The psychological dimension is also deliberate. By associating Poseidon with apocalyptic imagery, radioactive tsunamis, irradiated coastlines, autonomous drones lurking on the ocean floor, Russia projects technological daring and strategic unpredictability. Whether the weapon performs exactly as advertised matters less, in deterrence terms, than whether potential adversaries believe it might.
What still needs to happen before the picture clears
As of June 2026, the most responsible reading of the evidence is cautious but not dismissive. Russia has clearly invested heavily in a nuclear-powered underwater drone and tested it from a submarine. The United States has treated the program as real and strategically relevant at the highest levels of government. Yet the most dramatic claims about Khabarovsk’s specifications and Poseidon’s destructive potential rest on secondary analysis, not verifiable primary documentation.
Several developments could sharpen the picture. Official Russian Navy commissioning announcements for Khabarovsk, if they come, would confirm the submarine’s operational status. Arms control negotiations, should they resume after the expiration of New START in February 2026, could potentially bring novel delivery systems like Poseidon into a verification framework for the first time. Independent satellite imagery of Khabarovsk operating away from Severodvinsk would signal that sea trials have progressed beyond the shipyard.
Until then, the distinction between what is known and what is inferred remains essential. That distinction does not diminish the stakes. Even as a partially proven system, Poseidon signals a continued erosion of the boundaries that once constrained nuclear innovation. Russia is testing not just new hardware but the norms that govern how nuclear powers signal, threaten, and reassure one another. The next phase of that competition is unfolding far below the ocean’s surface, in an environment where verification is scarce and uncertainty itself becomes a strategic weapon.
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*This article was researched with the help of AI, with human editors creating the final content.
