Key point: It could also be conventionally armed and fired against surface vessels.
The Russian Navy is on track to deploy up to 32 of its “Poseidon” thermonuclear drones across four submarines, according to Russian state media.
Citing a military insider source, TASS reported earlier this week that "Two Poseidon-carrying submarines are expected to enter service with the Northern Fleet and the other two will join the Pacific Fleet. Each of the submarines will carry a maximum of eight drones and, therefore, the total number of Poseidons on combat duty may reach 32 vehicles."
Poseidon is an underwater drone weapon, armed with a 2-megaton nuclear or conventional payload that can be detonated “thousands of feet” below the surface. This is meant to generate a radioactive tsunami capable of destroying coastal cities and other infrastructure several kilometers inland.
Poseidon can remain submerged at up to one kilometer, travels at a maximum speed of 200 kilometers per hour, and is programmed to execute three-dimensional evasive maneuvers in response to interception attempts.
When unveiling Poseidon at his March 1st weapons address, Russian President Vladimir Putin was especially keen to stress the drone’s maneuverability: “We have developed unmanned submersible vehicles that can move at great depths – I would say extreme depths – intercontinentally, at a speed multiple times higher than the speed of submarines, cutting-edge torpedoes and all kinds of surface vessels.”
While the full range of Poseidon-compatible submarines has not yet been revealed, the TASS report confirmed that one of Poseidon’s first fittings will be the Project 09851 Khabarovsk submarine. Oscar II-class submarines will also fit Poseidon "after their appropriate upgrade," though it isn’t clear how many Oscar-II vessels will be repurposed to this end. TASS asserts that the each of these submarines will be able to carry and deploy up to 8 Poseidon drones.
Poseidon’s precise mega-tonnage has varied wildly over the years, with reports ranging from 100 to 2, but even several megatons would be enough to destroy major coastal cities if Poseidon works as described.
The more serious charge against Poseidon is that it doesn’t add anything to the Russian arsenal that traditional ICBMs and hypersonic gliders like Avangard don’t already offer. It is true, after all, that the latter boast a larger blast radius and reach the United States in less than an hour even as Poseidon takes several days at best.
However, there are strategic benefits to a weapon like Poseidon that may not be readily apparent. First and foremost, Poseidon enhances Russia’s nuclear threat by diversifying its first-strike capability. That is, the Russian military believes that it travels too fast and too deep underwater to be intercepted by torpedoes or otherwise countered. To the Kremlin, Poseidon is yet another way to circumvent America’s formidable strategic missile defense network.
But even if countermeasures can reliably prevent Poseidon from destroying coastal cities, it still possesses a large destabilizing potential. For example: detonating Poseidon off America’s coast will at the very least inflict mass political panic and military confusion, which can be used as cover for a different offensive operation.
Secondly, Russian media have floated the possibility of Poseidon being deployed against aircraft carriers and other surface vessels; to this end, it can be armed with a conventional payload. Depending on Poseidon’s production costs and price-to-performance numbers, this can prove to be a more cost-effective way to neutralize carriers than swarms of conventional air and surface-launched missiles. Finally, the unconventional threat posed by Poseidon may be a source of Russian leverage in ongoing arms reduction talks with the US.
Still, Poseidon is by no means a decisive advancement of Russian nuclear capabilities. What it does offer-- provided that it lives up to its technical potential-- are strategic benefits that can complement Russia’s nuclear and conventional flexibility.
Mark Episkopos is a frequent contributor to The National Interest and serves as a research assistant at the Center for the National Interest. Mark is also a Ph.D. student in History at American University. This article first appeared last January.