North Korea is attempting to develop submarines capable of launching nuclear armed ballistic missiles, Debalina Ghoshal writes for USNI News.

North Korea is developing a new class of submarines based on the designs of the Soviet-era Golf-II class submarine.

Although these vessels have been surpassed by later US and European models and are basically obsolete by modern standards, North Korea is gaining technological insight from the submarines that could lead to a functioning ballistic missile vessel.

As Ghoshal writes:

[T]hese submarines would be able to fire ballistic missiles. In fact, reports confirm that Pyongyang already is developing a vertical-launch system for submarine launched ballistic missiles (SLBMs). Raising further concerns about that is the fact that North Korean ballistic missiles could be armed with nuclear warheads.

This interest in a sea-based missile capability comes not long after a top US general claimed that North Korea had made progress on miniaturizing its nuclear warheads, which are widely thought to be too large and unwieldy to deliver by the ballistic missiles Pyongyang currently possesses.

In October, US General Curtis Scaparrotti, the commander of US forces on the Korean peninsula, warned that North Korea had developed “the capability to miniaturize a device at this point and they have the technology to actually deliver what they say they have.”

If North Korea completes its reserve engineering of the Golf-II submarines, the Hermit Kingdom could field a fleet of nuclear-capable submarines that could function as an additional deterrent.

There’s reason for skepticism, though. For the foreseeable future, the threat of nuclear retaliation from North Korea remains isolated to the North East Asian region, and that’s assuming its nuclear weapons are small enough to be practically deliverable. North Korea lacks a proven capability of launching a missile that could strike the continental US, although the country could possibly target US forces stationed in bases throughout the Asia Pacific region.

But even in North East Asia, the threat from North Korean submarines remains low. Pyongyang is years away from creating a fully credible sea-based nuclear fleet, and that’s assuming they master nuclear miniaturization. And after construction of this hypothetical fleet, North Korea’s submarines would be outdated and potentially easy prey for more advanced submarine hunting equipment. Pyongyang would still be running a North Korean version of an outmoded Soviet model.

“Because the submarines have been reverse-engineered from the obsolete Golf-class submarine,” Ghoshal writes for USNI News, “there is a chance that the submarine could be defeated by modern anti-submarine techniques.”