There is a corner of North Korea’s nuclear program that we should take notice of. Hidden behind the distraction of the recent spate of tactical missile tests is a greater development with strategic implications: New submarines that will allow the Hermit Kingdom to improve the lethality and survivability of its nuclear arsenal.
Kim Jong-un inspects the new submarine. The blurring was applied by North Korean censors.
On July 23, North Korean state media released images of Kim Jong-un inspecting a submarine. The boat (submarines are always called boats) was described as newly constructed, although it is likely an old boat that has been newly modified. The images, which do not show the entire submarine, can nonetheless be pieced together to reveal that it is a variant of the 1950s vintage Russian Project 633 submarine, known to NATO as the Romeo class. North Korea has operated as many as twenty of these submarines, with most being built locally with Chinese assistance. The last local construction was in 1996. The age of the underlying design notwithstanding, it appears to have a new capability that should energize strategists: it looks like a ballistic missile submarine.
This is beyond reasonable doubt. Stitching together the handful of images we can see the tell-tale signs. North Korean state media attempted to obscure this but trained eyes can see through the blurring. On top of the enlarged sail in the middle of the submarine are a series of small holes. These are to allow water to escape sideways when a missile is launched and was a feature added to an earlier submarine after some test launches. Together with an in-depth analysis of the likely interval arrangement of the hull we can be confident that this is a ballistic missile submarine.
Placing part of North Korea’s nuclear arsenal aboard submarines greatly increases their survivability in the event of conflict.
All countries with a nuclear arsenal have sought to do this to some extent, and North Korea launched its first missile submarine in 2014. That submarine only carries a single missile and is primarily seen as a test platform. This new submarine has room for three missiles, indicating an operational role and greatly increasing the chances of a missile penetrating any defenses.
The submarine will probably carry three KN-11 ballistic missiles, which have an estimated range of 1,250 kilometers (775 miles). Perhaps not coincidentally North Korea has named this missile the Pukkuksong-1 which translates into Polaris-1, the same name as the United States Navy’s first operational submarine launched ballistic missile. The missile range is enough to threaten U.S. forces in the region from the relative protection of its home waters, but the submarine would have to break out into the Pacific to directly threaten Hawaii, Guam or the Western seaboard of the United States. It would have the range to do this, however.
The old design does come with some drawbacks. It is comparatively noisy, which means it’s less stealthy and so easier to attack. This will be particularly true when it’s running its diesel engines to recharge its batteries, which it will have to do often. It does have one trick up its sleeve, however: Unlike the nuclear-powered ballistic missile submarines used by the U.S. Navy, it can sit on the sea floor and go silent, making it very difficult to detect for a few hours or days while it is there.
The conversion of existing submarines to carry ballistic missiles is likely to be the fastest way for North Korea to achieve the goal of most nuclear countries’ planners: a submarine force which is continuously at sea. This means that in any future conflict there may be a certainty that some of North Korea’s nuclear weapons will be hiding beneath the waves, ready to strike at any moment.