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Interviews with experts: How capable are N. Korea’s subs, missiles?

  • September 8, 2016
  • , The Japan News , 2:13 p.m.
  • English Press

North Korea has been repeatedly test-firing submarine-launched ballistic missiles, or SLBMs (see below). On Aug. 24, an SLBM launched off Sinpo, a city in northeast North Korea, flew for about 500 kilometers. If fully deployed, these missiles pose a serious security threat to Japan, the United States and South Korea. The Yomiuri Shimbun interviewed experts on North Korea’s SLBMs.


(From The Yomiuri Shimbun, Aug. 28, 2016)


Concerns over nuclear umbrella’s credibility


Toshiyuki Ito / Former Commandant of Maritime Self-Defense Force’s Kure District


North Korea’s SLBM program is steadily progressing. Looking at footage released by North Korea, a missile ignited the moment it cleared the water and flew smoothly. This was the most difficult part, and probably relied on technology provided by the former Soviet Union. North Korea is now able to reproduce that technology.


The SLBM may be the same type as a Musudan medium-range ballistic missile. The Musudan is widely believed to be a variant of the R-27 SLBM purchased from Russia that has been modified for land-based launches. A series of launches have been carried out since spring, and a missile reached an altitude of 1,000 kilometers for the first time in June.


North Korea’s SLBM was launched from a Sinpo-class submarine. Although it was modeled on a Golf-class submarine made in the Soviet Union, the crucial launch equipment was removed prior to purchase. According to U.S. reports, North Korea later purchased missile launch equipment and modified the submarine so that equipment could be installed, creating the Sinpo class.


The submarine’s hull is roughly six meters in diameter, and the bridge is about six meters high. As the Musudan is about 12 meters long, it can be installed vertically. Therefore, the recently launched SLBM was also likely fired from a Sinpo-class submarine.


Submarine construction is not easy. One of the most important factors is resistance to water pressure. In order to make the hull withstand extreme water pressure, steel plates must be molded into a true circle and welded to avoid leaving any gaps. Only a few countries, including Japan, are capable of building submarines on their own.


The Sinpo class is most likely a battery-powered submarine of about 2,000 tons. It can only dive to shallow depths and operate in coastal waters. I believe it is incapable of venturing far into the Sea of Japan, let alone the Pacific.


Technically speaking, it is virtually impossible for North Korea to send its submarines into the Pacific and approach the U.S. mainland in the near future.


What North Korea wants most is to develop the KN-08 intercontinental ballistic missile, which uses improved technologies from its advanced Taepodong-2 long-range ballistic missile and is capable of reaching the U.S. mainland. If it can do this, North Korea believes it will be on an equal footing with the United States in terms of nuclear deterrence.


With Musudans and SLBMs, which are still in an experimental stage, the objective is to achieve a range of 4,000 kilometers. The intended target is not Japan or South Korea, but rather Guam, a strategic base for the U.S. military. It will be sufficient if SLBMs launched off the coast of Sinpo — like the most recent launch — could reach Guam.


In terms of nuclear deterrence, the significance of SLBMs lies in their second-strike capability. In other words, even if a country’s ground-based nuclear capabilities are destroyed in a first nuclear strike, nuclear weapons at sea can be used in a second strike against the enemy. Theoretically, this is how they work as a mutual nuclear deterrent.


If North Korea’s SLBMs were to achieve full combat capability, the credibility of the U.S. nuclear umbrella could be undermined. This is because it could lead to such doubts as, “Will the United States really carry out a nuclear strike against North Korea in order to defend Japan?” or “Will the United States hesitate to carry out a nuclear strike against North Korea out of fear that Guam will be hit by a second strike?”


For Japan, the prospect of the nuclear umbrella being disregarded can be considered a threat.


(Taken from an interview conducted by Yomiuri Shimbun Senior Writer Tatsuya Fukumoto)


Ito’s profile


After serving as captain of the MSDF submarine Hayashio, Toshiyuki Ito retired as a vice admiral and commandant of the MSDF Kure District in August 2015. He is now a professor at the K.I.T. Toranomon Graduate School and a visiting research fellow at the Canon Institute for Global Studies. He is 58.


Keep focus on submarine developments


Yang Uk / South Korean commentator on military affairs


To determine whether the recent SLBM launched by North Korea was a “success,” the weapons system and the missile launch need to be evaluated separately.


Regarding the missile launch, great obstacles have been overcome and it can be said with near certainty to have been a “success.” However, its success as a weapons system is another matter.


Three criteria must be met in order to have SLBMs. These are (1) the missile launch, (2) the nuclear warheads, and (3) the submarines from which to launch the missiles. Currently, it is fair to conclude North Korea has succeeded in completing (1) and could probably be said to have successfully met the criteria for (2), with four nuclear tests.


Although the SLBM launches in April and July are widely regarded as “failures,” this is not necessarily the case. It is possible that the April and July launches were experiments in which the missiles were intentionally exploded at certain altitudes, as was done with Scud and Rodong launches.


The problem for North Korea now is (3), submarines. In order for SLBMs to work as a deterrent, submarines need to be capable of remaining submerged for long periods of time.


Although North Korea possesses a large number of submersibles and submarines for landing and launching anti-ship torpedoes, when it comes to submarines capable of launching missiles it only has one outdated submarine that can remain at sea for only two to three days. It will, therefore, likely be some time before they are capable of building a successful weapons system.


Be that as it may, North Korea first introduced submarines in the 1960s and has produced all of them at its Sinpo submarine base. Over the years, they have accumulated a considerable amount of production technology. The submarine currently installed with missile launch tubes is based on a Golf-class submarine purchased from Russia in the early 1990s following the collapse of the Soviet Union.


For SLBM-equipped submarines to be useful in actual combat, they require at least two missile launch tubes and an air-independent propulsion (AIP) system, which enables submarines to continually navigate underwater without surfacing.


It is believed that North Korea is currently constructing a 3,000-ton class submarine equipped with such features. Satellite images show construction of some sort is being carried out at Sinpo’s shipyards.


North Korea has continued to launch land-based missiles and apply those technologies to SLBMs, judging by the fact that the Musudan and SLBM are almost identical in appearance.


The nuclear powers of the United States, Britain, France, China and Russia all possess SLBMs. By completing its own SLBM, North Korea is seeking global recognition as a nuclear power.


If North Korea’s submarines become capable of venturing out into the open seas, constant monitoring patrols will be needed.

Japan has the best patrol capability in Northeast Asia. As South Korea lacks such capabilities, patrols may become the starting point for security cooperation between the two countries.


(Taken from an interview conducted by Yomiuri Shimbun Seoul Correspondent Kentaro Nakajima)


Uk’s profile


Yang Uk graduated from Seoul National University and gained a master’s degree from the Korea National Defense University’s Graduate School of Defense Management. Among other positions, he serves as a senior researcher at the Korea Defense and Security Forum, and as a policy advisory committee member of the National Defense Ministry. He has authored a number of books, including on national security and weapons. He is 41.

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